Mails from local server not being delivered properly - email

I have a local phabricator server which triggers mail for every commit and email is generated through postfix and emails are delivered to Office 365 accounts. I observe that some mails are not being delivered. Only 60% of them are being delivered approximately. How can I fix this issue?

Related

Cpanel This message could not be delivered

I'm interesting to host my website portal at home, I've got public ip from my isp, got good server, installed cent os, installed cpanel, copied website but seems that email server not working good.
When testing to multiple receivers, few mails are delivered ok but few message are not delivering, example of errors:
error1:
SMTP error from remote mail server after initial connection: 554 n1plibsmtp01-02.prod.ams1.secureserver.net bizsmtp IB106. Connection refused. MYIP is listed on the Policy Block List (PBL).\302\240
error2:
ECDHE-RSA-AES256-SHA384:256 CV=yes: SMTP error from remote mail server after MAIL FROM:MYEMAIL SIZE=1669: 550 DY-001 (COL004-MC2F3) Unfortunately, messages from MYIP weren't sent. Please contact your Internet serv
error3:
ECDHE-RSA-AES256-SHA384:256 CV=yes: SMTP error from remote mail server after MAIL FROM:MYEMAIL SIZE=1669: 550 DY-001 (BLU004-MC1F26) Unfortunately, messages from 213.163.119.60 weren't sent. Please contact your Internet ser
Delivered emails have this message:
Accepted
So since few emails are delivered and few emails are not delivered, seems blocked by hotmail, gmail, yahooo, or marked as spam.. means that problem is to my ISP?
Services like Gmail, Outlook.com and Yahoo! Mail block email to protect from unwanted or malicious email such as phishing, scams and spam. In this case, they are mistaking email that you are sending.
There is something like "whitelisting domain" but I am not too sure on that. I think that can help ??

Stop re-trying bounced emails in SMTP

I am developing a bulk email procedure, in that I have no issues in sending emails in batches. My problem starts when the recipients address is invalid or rejected by the host server.
Simply how can I tell the SMTP server not to retry it the original email was bounced.
I can only use MS Exchange Server.
The number of retries is a setting that you can configure in MS Exchange. See: http://technet.microsoft.com/en-us/library/jj891103(v=exchg.150).aspx

SMTP Mail Failures to a certain domain

Do the SMTP logs on a server (Windows 2003) only show logs of mail that were sent successfully?
We are getting bounce backs when sending mail to a particular domain:
The connection was dropped by the remote host.
It looks like a problem on the receiving server, but we dont have much information to provide them. We can send to hotmail, gmail, yahoo etc OK.
Any ideas?
Most likely, there is a spam filter in front of the receiving mail server for this domain, and this spam filter thinks your mail server is sending spam, so it's closing the connection from your mail server. One way to test this is to simulate sending a message to this mail server by opening a command prompt on your mail server, and use telnet to connect to the receiving mail server on port 25, and proceed with the process of sending a message just as a mail server would. This way, you'll be able to see how the receiving mail server responds after each step. Follow the instructions in http://support.microsoft.com/kb/153119 to see how this is done.
It turned out the sending server was blacklisted by McAfee, that was running on the receiving servers firewall.
For those that may have the problem in the future you can check if your server is blacklisted with McAfee here:
http://www.mcafee.com/threat-intelligence/ip/spam-senders.aspx
After entering your server IP, you should see a link Threat Feedback. Use this to email McAfee.
I was able to send McAfee an email with an explanation, they then removed our server from the blacklist.

Switched exchange servers, kept the same e-mail but some incoming mail is still going to the old server

I recently switched from an axoim exchange mail server to microsoft 365 exchange server. Now my email address is still the exact same as it was, and most of the incoming mail comes to my new server and address, but it looks like some incoming mail is still going to the old server. Why is that and what can i do to address it?
I'm assuming that you changed the MX records for your domain, so that they now point to Microsoft 365's mail servers, correct? If so, it may take a day or two for the DNS changes to propagate.

SMTP outbound emails stuck in Queue folder : Windows XP SP3, IIS 5.1

I am using a PHP script for sending emails by IIS 5.1 SMTP.
The emails, go to outbound folder. really path is C:\Inetpub\mailroot\Queue.
after a seconds, it start to send emails properly, but after sending 5 or 6 emails, it stops to send the other ones. SMTP service is still start and it seems there is no problem to SMTP service.
but,If i restart the service, it sends 1 or 2 other emails and then, it stops again.
I mean sending emails stop but service is start.
by the way, emails are stucked in Queue folder.
Also i checked Badmail folder. it is empty
Thanks
are all the emails to the same network? I have seen behaviour like this when the recipient server bans you, yahoo's (xtra) used to do it sometimes to our server in particular. You can check the logs in event viewer for something from the smtp server, you'll find a message from the other server saying something to the effect that you have been temporarily banned, possibly with more detail about why. Trying to connect via telnet also gives you the same message.
When this happens windows will try and send them again later. Restarting the server starts to try sending again and if the ban condition has been lifted messages will flow for a while again until you are rebanned.