I have a VB6 app which is used by a large number of clients.
I need to allow the clients to be able to send emails to me. In the past I have done this using Microsoft MAPI controls. However, not all of them have an email client installed, since they use webmail instead.
Is there any other method anyone can recommend which would allow them to do this?
SMTP
You can use CDO for Windows to do this if we make a few assumptions:
Your users are all on Win2K or later.
The users will never be behind a firewall blocking SMTP or proxying all SMTP port use to a corporate server.
You have an SMTP server that you have an account you can let the user-mails be sent with.
You embed the server's address and account credentials in your program.
Sometimes using an SMTP server listening on an alternate port will address the second issue, but often such an alternate port is even more likely to be blocked.
SMTP is Dying
Abuse over time has made SMTP less and less viable for automated/assisted user contact. There are just too many variables involved in trying to open some sort of "clear channel" for SMTP communication as people work harder to fight spammers and such.
Today I would be much more likely to use either WebDAV or a Web Service for this. Both use HTTP/HTTPS which is more likely to get past firewalls and usually get by most proxy servers as well. WebDAV is often more "slippery" at this than Web Services, which more and more proxies are bocking. You can also use something more RESTful than SOAPy since the traffic "smells more like" user browsing to proxy servers.
WebDAV is a Clean Option
There are even free WebDAV providers offering 2GB of storage with a main and a guest user. The guest account can be given limited rights to various folders so some folders they might post your messages to, other folders they might get data from (read only folders), etc. For a paid account you can get more storage, additional users, etc.
This works well. You can even use the same hosting for program version files, new version code to be downloaded and installed, etc. All you need on your end is an aggregator program that scoops up user posted messages and deletes them using the main user/pw.
You still need to embed user credentials in your program, but it can be a simpler matter to change passwords over time. Just have the program fetch an info file with a new password and an effective date and have the program flip the "new" password to "current" once run on that date or after.
WebDAV support in Windows varies. From WinXP SP3 forward you can simply programmatically map a drive letter to a WebDAV share and then use regular file I/O statements against it, and unmap the letter when done. For more general use across even Win9x you can build a simple WebDAV client on top of XMLHTTPRequest or use a 3rd party library.
Web Services Have Higher Costs
Just to start with you have server-side code to write and maintain, and you have to use a specific kind of hosting. For example if you built it using PHP you need a PHP host, ASP an ASP host, ASP.Net an ASP.Net host, etc.
Web Services can also be more problematic in terms of versioning. If you later update your program to provide different information in these user contact posts you have to make another Web Service as well as changing both the application and the aggregator. Using WebDAV you can just make a "new format" folder on the server and have the new program post the data there in the new format. Your aggregator can simply pull from both folders and do any necessary reformatting into your new local database/message repository format.
This is merely an incremental additional effort though and a Web Service might be the way to go, even if it is just something written like an HTML Form GET/POST acceptor.
Although this question is for VBA you may find it of interest. Sending Emails using VBA without MAPI
Related
How to implement a bot with ejabberd?
The idea is that on my (Debian 7.0 Wheezy) VPS, I'm running ejabberd and there I have a special bot Jabber user with limited set of commands that he can run. Let's call him butler#myvps.foo.
On another box (say, my android phone), I have a Jabber client connected to my account at possibly a third party server. Let's call it me#somewhere.bar.
Now I want ejabberd to:
allow only one specific Jabber ID, me#somewhere.bar to ever communicate with this
butler#myvps.foo.
have everything typed into chat with butler#myvps.foo passed to shell and executed
as a command, possibly in a chrooted or another protected environment (e.g. using
a specific limited user). (And the STDOUT + STDERR returned as a reply, of course.)
I understand there can be security risks, but for now I just want to know if this the way to go.
You can simply write a bot in any language and have it connect to the XMPP server as a client. A list of XMPP client libraries can be found here.
The bot can check the JID in the 'from' attribute of messages it receives to verify identity. It is not generally possible to forge a JID in XMPP, as servers authenticate their clients and also each other. In reality however it is only as secure as the authentication methods used (and the server containing no bugs).
To execute commands and read the results, a PTY is a good easy solution. There are PTY libraries available in many languages, including Python, Ruby and Lua.
You are right that security is an issue, as with any system. Years of effort have gone into securing ssh, and issues still arise occasionally.
It is worth noting that Google's XMPP server does not support encryption for server-to-server connections, so someone on a network between your XMPP server and Google's would be able to see your messages, and potentially modify and/or forge them completely.
And finally, even if they did support encryption for the server-to-server link... Google themselves technically have the ability to send messages as you, and your phone would also be a potential weak point.
Isolating the target process will remove a lot of security concerns. If the server runs on Linux, LXC containers might be a good solution for you.
Hopefully this covers all aspects of your question!
We currently have POP3 mail accounts where I am and try as I might to convince my manager that we should be using hosted IMAP or Exchange he won't budge because of the cost. The staff are mostly out of office so there is no domain server here, however, we do have a dedicated server and I wondered whether I could use this to collect the mail and distribute it from there in some way.
Effectively what I'm trying to do is ensure mail is stored somewhere other than the end users machine because backups are user dependant at the moment. With hosted Exchange or Exchange on this server would be simple but my manager won't shell out for it. I have seen free mail servers called MailEnable and Axigen but unsure if they will do the job. Sorry if this seems like an easy or stupid question but never needed to do this before.
I am assuming due to the reference to Exchange that you are on Windows.
If you have an old box lying around that works, you could install linux on it and then choose from a number of different imap servers. Dovecot and Courier are both good choices and I have worked with them before.
You could use fetchmail to then pick up the mailboxes and then deliver to the imap boxes or get them deliver directly.
Setting up such a linux server for email was one of the first things I ever did on Linux. While initially daunting, once you get the hang of it, it is pretty straightforward and there are plenty of resources out there to help.
Ubuntu is probably the easiest to get used to. CentOs is also a reasonable choice.
You shouldn't be running your own server if you aren't willing to administer your own server, and they are not easy to configure if you don't know what you are doing (e.g., you mess up and you are exploited for spamming).
Look into a service like mailgun. In my application we are using them for forwarding to REST endpoints as well as onto another SMTP server.
Competitors that wound up not meeting my needs but may meet yours include Dyn, email yak, Sendgrid, etc. etc.
Why not just setup the mail clients to store their mail files on a standard network drive or share? I follow that this situation is pretty silly in your view - 100% because of the ridiculous constraints that you are being asked to work within: I would similarly find the solution I am suggesting ridiculous generally; but under the circumstances, it seems like a simple answer to your problem - replacing distributed mail storage and backup with centralized storage and backup.
Don't POP3 email clients have the option keep a copy on the server? Mine certainly does. See second tick box on the pic.
You can then periodically take a back up of all the emails from the server to stop it getting clogged up.
A client is moving from their old hosting to mine. They have a few email accounts on the old hosting and I want to move all the emails on the old hosting to mine. How can I do this? If I download them with POP can I then upload them to the new hosting?
The answer depends on the mail server that you are using. Yes, you can download all the mail messages with POP3, but the upload to your mail server will depend on the type of mail server. I am not aware of any mail servers that provide a tool to import mail messages.
Most mail servers store the email message in a file, and you can certainly drop the files in the folder where they are stored, but that does not mean that it will be visible, you will have to deal with how the mail server index those files.
I suggest looking at the specifications for your mail server.
If you access both accounts with IMAP (most hosts support this now) instead of POP, you can literally drag and drop the messages between folders/inboxes for the two email accounts.
Also, depending on the type of hosting they're moving from/to, you may be able to use a feature of your new server's control panel to do the importing...unless you're doing it manually on a vanilla VPS or dedicated. There are still options, but you'd need to confirm here how your new server is setup and what the old server looks like.
If you're only talking about a couple of accounts with a few folders each, you may just want to consider IMAP as your path of least resistance. The transfer will primarily depend on your own Internet connection, as most hosting companies have connections faster than yours.
Lastly, if both servers share a similar format for the mailbox, you might want to just rsync the email over to the new server (assuming you have root access on both servers) to the proper email directory. Depending on the email box format, you may be able to simply run a server command to "convert" the mailbox to the format your server is expecting.
I am trying to build an application that can inform a user about website specific information whenever they are visiting a website that is present in my database. This must be done in a browser independent way so the user will always see the information when visiting a website (no matter what browser or other tool he or she is using to visit the website).
My first (partially successful) approach was by looking at the data packets using the System.Net.Sockets.Socket class etc. Unfortunately I discoverd that this approach only works when the user has administrator rights. And of course, that is not what I want. My goal is that the user can install one relatively simple program that can be used right away.
After this I went looking for alternatives and found a lot about WinPcap and some of it's .NET wrappers (did I tell you I am programming c# .NET already?). But with WinPcap I found out that this must be installed on the user's pc and there is nog way to just reference some dll files and code away. I already looked at including WinPcap as a prerequisite in my installer but that is also to cumbersome.
Well, long story short. I want to know in my application what website my user is visiting at the moment it is happening. I think it must be done by looking at the data packets of the network but can't find a good solution for this. My application is build in C# .NET (4.0).
You could use Fiddler to monitor Internet traffic.
It is
a Web Debugging Proxy which logs all HTTP(S) traffic between your computer and the Internet. Fiddler allows you to inspect traffic, set breakpoints, and "fiddle" with incoming or outgoing data. Fiddler includes a powerful event-based scripting subsystem, and can be extended using any .NET language.
It's scriptable and can be readily used from .NET.
One simple idea: Instead of monitoring the traffic directly, what about installing a browser extension that sends you the current url of the page. Then you can check if that url is in your database and optionally show the user a message using the browser extension.
This is how extensions like Invisible Hand work... It scans the current page and sends relevant data back to the server for processing. If it finds anything, it uses the browser extension framework to communicate those results back to the user. (Using an alert, or a bar across the top of the window, etc.)
for a good start, wireshark will do what you want.
you can specify a filter to isolate and view http streams.
best part is wireshark is open source, and built opon another program api, winpcap which is open source.
I'm guessing this is what you want.
capture network data off the wire
view the tcp traffic of a computer, isolate and save(in part or in hole) http data.
store information about the http connections
number 1 there is easy, you can google for a winpcap tutorial, or just use some of their sample programs to capture the data.
I recomend you study up on the pcap file format, everything with winpcap uses this basic format and its structers.
now you have to learn how to take a tcp stream and turn it into a solid data stream without curoption, or disorginized parts. (sorry for the spelling)
again, a very good example can be found in the wireshark source code.
then with your data stream, you can simple read the http format, and html data, or what ever your dealing with.
Hope that helps
If the user is cooperating, you could have them set their browser(s) to use a proxy service you provide. This would intercept all web traffic, do whatever you want with it (look up in your database, notify the user, etc), and then pass it on to the original location. Run the proxy on the local system, or on a remote system if that fits your case better.
If the user is not cooperating, or you don't want to make them change their browser settings, you could use one of the packet sniffing solutions, such as fiddler.
A simple stright forward way is to change the comupter DNS to point to your application.
this will cause all DNS traffic to pass though your app which can be sniffed and then redirected to the real DNS server.
it will also save you the hussel of filtering out emule/torrent traffic as it normally work with pure IP address (which also might be a problem as it can be circumvented by using IP address to browse).
-How to change windows DNS Servers
-DNS resolver
Another simple way is to configure (programmaticly) the browsers proxy to pass through your server this will make your life easier but will be more obvious to users.
How to create a simple proxy in C#?
I'm looking to start using an SMTP or mail relay service. I've found quite a few out there, but I'm not sure if there are advantages to one vs another. The only requirements I have are:
can send "from" more than 1 domain (possibly >20 for all the different sites I work on)
can pay for a higher limit (I may need to send as many as 15000 in 1 day, although the average is <500)
can send from PHP (although I doubt this will be a problem as most are compatible with any language)
I'm okay with an SMTP service, mail relay service or a site that uses a custom API, although an API would make the conversion more difficult.
Reasons for wanting to do this:
I don't want to host any mail services my self as they just cause head aches
I don't have to worry about being blacklisted. If they are blacklisted they will know about it and have the knowledge to get it fixed.
Reporting on if emails have gone through would be nice.
I'm not sure why you would need this. If you read the proper RFCs (822, 2822, 823, 2823), you should be able to connect to any given site directly using SMTP. You need to be a little careful with Line Endings (should always be CRLF), and should probably add mail.add_x_header = OFF to your php.ini.
However, if you need a relay, I recommend using a spam filtering provider, as then you have protection from being blacklisted due to spammers abusing email-generating forms. I would recommend Red Condor for this task, but that is only because I work there, and know that we can handle it.
I've started using Mandrill and found it to be a great, reliable service provided by MailChimp that includes enough for most sites to use for free. Easy to setup, but also has a lot more functionality available.