I have been successfully using Sendgrid through Azure to send critical system updates to my clients for some time. All of my emails have suddenly started to become 'Deferred' before either being sent or blocked. I've done some research and there is a chance that my email address has been put onto a Blacklist. All of the emails sent are just, and are in no way spam.
How do I check if I'm on a blacklist and resolve the issue? I know that there are sites out there but I don't want to sign up for any scam services.
No response from SendGrid support so I updated to the 'Silver' offer which supplies me with a dedicated IP address (and fixed the problem). I believe that the problem came from the fact that I was using a shared IP (supplied by SendGrid) as part of the lower package.
Related
I have a problem with a web server, that also sends newsletter emails with an unsubscribe link.
Everytime such an email is sent out, the unsubscribe link is called directly. Because it could be 1000 or more email, the calls crashes the server everytime.
All emails are directly sent to Trend Micro Hosted Email Security.
First I thought, there is malware on the machine, but checking for that gave no result. I now changed the machine, but it happens also with a completly new machine.
The ip addresses of that calls are all from Amazon Webservices. I blocked a lot of this ip ranges already, but that is no góod solution.
What kind of server attack is that? What can I do, to stop or at least handle it?
I'll appreciate your hints.
Thanks
Vera
This looks like your emails are all going through some sort of email security scanning service, either on your servers, or on the recipient's servers. Typically, these scanners will also scan any links present in emails to ensure they are not malicious. There is no great solution to this. If you are scanning all your outgoing emails, you disable that, which may or may not be a good idea. See also Strategies to prevent email scanners from activating "unsubscribe" links.
I have a question about the email deliverability to primarily Gmail and to some extent, Yahoo and Outlook email users. It’s a bit long since I’d like to lay down what I’ve done and tried so far, so please bear with me.
The Issue: Our marketing emails (in newsletter format, in hotel industry) using several email IaaS and PaaS are ending up in spam for Gmail users. About 10% will receive in Promotions tab.
The Providers: Here are the email IaaS and PaaS services I have been trying so far.
SendGrid (we are using their email API)
SparkPost
Mailgun
ElasticEmail
With each platform:
I’ve tried both our own dedicated IP addresses AND the platforms’ shared IPs.
New domains that haven’t been used to send emails
Changed contents of the email completely, including the HTML code (by designing new ones, just in case it’s an issue)
DKIM, SPF and all are setup correctly for each domains we used
I’ve checked all the domains and IPs (both dedicated and shared) against known blacklists and spams using MXTools and such. Everything is okay.
We also checked the emails we’re sending using:
www.isnotspam.com
www.mail-tester.com
Both are recommended by SendGrid. We score highly on both, and according to the analysis results from both, our emails are not considered spam.
We’d also checked our domains and all IPs (both dedicated and shared, from any platforms we mentioned above) using SenderScore. Everything is fine here too.
For dedicated IPs, we did the warm up too. But the issue is, even if we are sending just 1-10 emails for testing and warm up, they do end up in Spam. We aren’t even sending to anyone unsolicited. In fact, just for testing purposes, we are sending emails to multiple email addresses owned by our internal team.
I’d talked at length with support team from SendGrid. After checking everything they could think of, they also stated that they can’t find anything amiss with our configs, settings, IP and domain reputation and their own infrastucture.
So what gives? I am really out of idea. Please help!
Thanks.
My team supports a website for a client, and we use SendGrid to send email related to the site on their behalf.
We do not have anything to do with their own email server and I don't at present know anything about it.
So far as I can work out, SendGrid has proper authentication and is an authorised sender for their domain, and almost 98% of email is delivered successfully.
However, we have had a handful of bounces with the reason "550 relaying denied" and all of these were to addresses at our client's domain (the same one as their website and the from address of the emails.)
Most emails to their domain were delivered successfully.
Unfortunately I don't have access to the full headers of the bounce emails, only the reason.
I understand that in general this error can either be caused by
the sender not being authenticated correctly. I am very far from being an expert in this but so far as I can tell, there is nothing wrong there. Or
a DNS or similar misconfiguration on the part of the recipient's email domain. I have even less understanding about this and I have no access or responsibility for the client's email server.
My main question is, is there any way the domain being the same as the from address could be related? Being as the email is claiming to be from the same place it's sent to, is it possible for that to affect how it's handled by relays?
If not, I'd also appreciate any pointers on where to look for the issue (or what to advise the client to look at if the problem is likely to be from their end.) I have been trying to research issues with email configuration and authentication but I am very much a novice in this area.
Thanks in advance.
The domain being the same could very well be related, but normally when that happens, the receiving server refuses all mail purporting to be from itself.
Separate from DKIM & SPF, most mail servers believe they alone are responsible for the mail from their domain.com. As such, a lot of them have anti-phishing filters that reject "outside" mail that claims to be from themselves. It's like "You can't be Carrie, I'm Carrie! Go Away!"
The fact that it's only some mail is interesting. The error being relay denied may also be key, though these anti-phishing filters often use "fake" errors to not give away the game.
Do the recipients of the messages that are being rejected have some kind of internal forwarding applied? That may be the cause, in which case that bounce reason is honest.
Or they may have a more defined anti-phishing feature, only rejecting mail From or For certain addresses. You can try testing certain combinations, and see if anything is repeatable.
Ultimately however, it will come down to working with the receiving mail domain's admin, and either updating those rules, or whitelisting the SendGrid IPs that are sending the mail to them.
Closed. This question needs to be more focused. It is not currently accepting answers.
Want to improve this question? Update the question so it focuses on one problem only by editing this post.
Closed 4 years ago.
Improve this question
In Cuba, web access is extremely censored, so I created a tool that allows more than 50,000 people to browse the Internet through email. Cubans send me an email with an URL in the subject line, and I email them back with the response. Read more at https://apretaste.com.
It was working like a charm, till the communist government of Cuba started blocking my emails. My solution was rotation.
I started with Amazon SES, and I was changing the domain each time it was blocked, but Amazon adds a header to all emails, and once they blocked the header no email from SES was able to reach Cuba any more. The same happened with Mailgun and others, they all add headers.
Currently I am creating Gmail accounts and sending via SMTP, but Google blocks me for no reason and only allows to send 100 emails a day per account. Also I can only create few emails using the same IP address/phone, so I was forced to use anonymous proxies and fake Chinese phones. Now I am fighting a war on two fronts.
An email can be blocked by three parameters: IP address, domain, and email address.
It will be terrific if I can set up my own Postfix server at a VPS that auto-rotates the IP address. Even better if I can simulate "gmail.com", to avoid purchasing a new domain every day.
All the intents to create what I call "the ultimate sender" just either reach the spam folder or add unwanted headers making it too easy to block. I feel exhausted. I hit a knowledge barrier here.
I know I am crossing to the dark side, but this is for a very good cause. Thousands count on this service as their only source of unbiased news, social network and to feel part of the 21st century.
Can you please help me implementing "the ultimate sender", or pointing to another solution that I may be missing?
I have a few suggestions for you.
The first one relies on The Onion Router also known as Tor.
Since you are crossing to the dark side, why not also take a look into the darknet?
Take a look at this list of Tor email providers. If you have your own email server that can be accessed through Tor, it becomes much harder for anybody to stop people from using this service. After all, Tor was developed to offer people uncensored access to the web.
You can read about Tor in detail here, it uses Onion Routing and this is how you would set up your server to use Tor.
Here is an example how you could use it:
The steps that involve the setup, receiving an URL request and sending back the reply are as follows:
Set up an email server.
Configure your email server to use Tor.
Publish the public service name. (e.g. "duskgytldkxiuqc6.onion")
Deploy a client that takes the service name and a URL, and let it send an email with a request to your server.
The client now waits for a reply.
You send a reply and the client receives it.
You can change your service name on a regular basis, but you need to make it accessible to those who will use this service.
Having an own email server means being able to control the email header.
Here is one example how you could make use of it:
Configure your email server so that it receives and recognizes
emails which contain the requested URLs.
Before you send a reply modify the email header so that it shows a random IP address and a random sender email address including a random domain name.
Send your reply.
Sending an email that way means that you cannot be replied back to. But since your reply already contains the requested information there is no need to.
I hope this helps.
Crowd source it.
Find a way that volunteers can send some emails for you. This is the only long term approach that I can think of. A simple web interface with mail to links would be be enough to get started although there are other potential problems with this approach too.
Because you are talking about low numbers of users, you could also use crowdsourcing to create the single email address per person approach. They can create an account on a specific set of email providers and give you the credentials. This would allow the single email per user approach or could be used to rotate through a large set of email accounts to send emails.
The simplest solution is perhaps to set up a local SMTP server on your own computer. You don't even need a server per se.
https://sourceforge.net/projects/winsmtpserver/
There are many other such applications. They are usually used to test SMTP functions during local development, but there is nothing against actually sending spam through them.
I know this would be quite a large task, but how about pairing the users with one or just a few emails so they always receive an email from that email.
I'd assume people wouldn't have more than 100 queries per day, if so they could start receiving them from a backup email
I'd imagine it would look less suspicious for them to appear to be in constant contact with one unique email rather than 50,000 being in contact with one
I know this would be a huge undertaking, but I feel like it solves your issue.
Since the users are willing to receive emails form you then your shouldn't be blocked.
When you mentioned you are getting block does it mean your mail is going in spam or is getting lost in between sending and receiving or it is getting bounced back??
My suggestion would be to setup your own mail server and follow as below:
-Get approx 25 or more ip to rotate. (IP is the most imp part which is tracked and is accountable for the reputation of your mail server)
Don't start sending emails in bulk from the word go it is better to gradullay increase the email volume so that mail server reputation nicely built
keep changing the format of the email often
encourage user to add yourself to there contact list
your best part is user are willing to receive emails from you and you would reply to revived email is the USP of yours but still i will recommend you to register for FBL so that you would know which user is reporting you as spam and you can remove him from your list and never send him email again.
using best practice to send emails like dkim, SPF, dmarc are also vital.
Hope my answer was of some help to you. If you need step by step guide to step up mail server let me know.
My friend, do you remember what made Hillary Clinton lose the last elections to Trump?
It was the "mail" affair. And what was it? People discovered she shared confidential information through a non-official, non-governmental email account (i.e., she used some Gmail, Yahoo or another of a kind). Until here, nothing new with direct relation to your matters. But there is an small particularity on this history, and this can put, maybe not a solution, but maybe a light on a new path you could follow: Clinton actually never sent those emails; the email account she used had the password shared and the communication between people (Clinton-someone) occurred only using the drafts of the account.
How? One side logs in and accesses the drafts folder. There he/she reads the last message and edits it, cutting and writing new data - then save the draft message. On the next turn, the other side of the communication line logs in and do the same. And so forth, so never really sending those messages, but instead just updating the drafts (this "Hillary" method does schooled people... Dilma Rousseff, impeached ex-president of Brazil, actually did this method down there in Brazil too).
So, maybe if you could establish a pact with your user that he/she doesn't delete the account's password, you could pass those information by this method - without "really" exchanging emails. Maybe a "parent" email account (some that could reset a lost password) could be useful too.
Alternative: aren't you able to contract a regular HTTP webserver? You could rely on FTP to publish data to your user, he/she asks for it and you publish a page with that content.
Salvi, have you tried something with Telnet? OK, we are talking here about a text-only environment, but if nothing more would rest in the future, this could be better than nothing. Maybe you could implement a podcast-like, or push-like service based on it. Look what people do with it with references to your walk on the dark side...
If in Windows, open your command prompt.
Type telnet and press Enter.
Type "o" without quotes and press Enter.
Type "towel.blinkenlights.nl" without the quotes and press Enter.
I'm making a user management system for my app, and I need to send users a "forgot my password" email with a token that lets them reset their account password. I signed up for SendGrid through Azure (to get the 25,000 emails per month free, which sounded like a great deal) and wrote some code to use it, but after testing my program a bit I was dismayed to find that only a couple of my emails actually went through.
After going onto the SG control panel, I found that 4 out of the 6 test emails I sent went through, and all of the others were rejected as being spam. I sent an email to mail-tester.com to see what it though my spam score was and it gave me a 4.3/10.
The email in question was a single sentence with a link to the password reset, without any images or other elements. I only sent those 6 emails out, so the volume of my emails definitely wasn't the issue. Still, I'm very puzzled as to why my messages are getting flagged as spam.
Without going to the trouble of making an elaborate authentication setup, are there any basic changes I can make to my system to make it get through to users?
In this case it's most likely because you are sending such a short message, with a link to 'reset your password' from a non-whitelabelled email address (the email address you're sending from cannot be verified against the actual domain), and the link may also be a different URL. It's probably getting pulled up as a potential phishing email.
You can rectify this by white labeling your domain and email links via the SendGrid dashboard, it's easy to do and should improve your deliverability.
Also check out this article from the SendGrid support team about White Labeling.
A question from 2015 which is sadly still relevant today as usage of SendGrid increases.
My organization has blocked all SendGrid mails except for those on the paid tier using fixed IP addresses with resolvable public DNS names (such as sendgrid1.sampledomain.tld) which we then whitelist.
There are now far too many domain impersonation, phishing and other spam mails coming in from SendGrid for us to allow everything from them - roughly 10 000 mails over a seven day period, which is far too many to manually report to SendGrids abuse department.
So my answer would be that switching to the paid tier of SendGrid is the better option if you like a better chance of your mails arriving intact at their destination.
I receive only Spam Mails from Sendgrid.
Goes direct to Spam folder and try to report Sendgrid everywhere I can. Maybe they get blocked by most mail servers and make them think about their policy in "hosting" all these Spammers.
In my case my emails are marked as spam because of the anchor label different to the href being actually called.
And that's because of the 'click tracking' setting of sendgrid.
So, if you have something like
yourdomain.com
sendgrid may replace the href and you end up with something like:
yourdomain.com
The sendgrid page being called tracks the click and then redirects the user to the url you originally set. But this sometimes results in your email being marked as spam.
Try to set 'click tracking' in sendgrid dashboard to off: settings | tracking | click tracking.
details here: https://sendgrid.com/docs/ui/account-and-settings/tracking/
Always start by setting up Domain Authentication, formerly known as domain whitelabel as #MartynDavies says. Found under Settings -> Sender Authentication in the UI. Should look like this:
https://sendgrid.com/docs/ui/account-and-settings/how-to-set-up-domain-authentication/
To identify problems have a look at Activity and choose to see deferred, drops, bounces, blocks and spam reports.
https://app.sendgrid.com/email_activity
Under Suppressions you can see details for Blocks and Bounces among others:
https://app.sendgrid.com/suppressions/blocks
https://app.sendgrid.com/suppressions/bounces
There you can see errors like:
550 5.7.1 SPF check failed. em1234.mydomain.com does not declare 11.222.33.44 as a valid sender
If it says Verified but you see errors like this then contact SendGrid support.
One thing that has worked is to upgrade from the Free plan to Essentials or Bronze via the Azure Portal. This made a lot of the emails marked as spam pass through.
I had a similar issue when trying to send a user verification email using SendGrid.
In my case, using a custom domain as the sender identity solved the issue.
Make sure to also verify the domain before using it.