I work with a dozen pieces of equipment whose operating software has the option to send e-mails on error. I would prefer to capture the details of that e-mail on the host PCs that run them (i.e. for logging, communicating details automatically via Slack, etc.) rather than them going to an inbox somewhere.
Is there a way to have the software e-mail an address that is essentially a lightweight piece of code running on the same PC mimicking something like an SMTP server (that will allow me to get after the message's contents)? Other solutions I have seen are along the lines of setting up a full-blown server which seems like overkill.
You may configure SmtpClient to save email to a specific folder instead of sending it over the wire. Check this answer.
Also you must design your system in the way it could work with different implementations of your 'sender', so that you can replace it when you need that, for example during testing. In this case you can easily provide proxy implementation that will capture email content and then send it to localhost, or add aspects (make retries, logs performance...).
Related
What needs to be done for an application to be able to issue email addresses, such as user123#mydomain.com?
I'm using Amazon SES to send out emails, do they have a service for this or would this have to do with the domain registrar (GoDaddy), or both?
The client to check email would be the web application itself.
I'm using C#.Net and Mvc for that as far as development is concerned but would prefer to use existing SaaS wherever possible.
What are some good ways to go?
EDIT: I checked with GoDaddy and they can't do this at scale. I don't believe Amazon does this either. How is this done?
This would all depend on your implementation of email server host. If you are running Windows with IIS and Email Post office then users are of the host domain. You can use the admin scripts for adding users from the site in this case.
If you are using Linux and a thrid party email service, it will likely have a user interface for adding users. Howerver these implementations generally use MySQL on the backend so you can add users through script from an implementation of PHP through Apache webserver host or backend service that adds users through MySQL script.
You need a mail server. As you can see from the list there are plenty of mail servers that exist, however there are some serious leaders in the field:
According to one survey, sendmail, Microsoft Exchange Server, Postfix,
and Exim together control over 85% of market share for SMTP service in
2010.1
I strongly recommend not hosting such a server in your code (if an implementation even exists, which I couldn't find)
After configuration of the mail server (which may need some intensive investment either in time or money, since this is complicated; some mail servers are notoriously complicated) you point your domain to the mail server. Mails can now be received to the email adresses you define.
This process is complicated, and I have a feeling that your question shows you don't know exactly what you need either (In fact I would have recommended closing it as too broad). I'd recommend reformulating exactly what you need and what you have so far. Don't hesitate to get in touch with someone that may help you formulate your needs.
I'm trying to understand exactly what it is I need to be implementing and am just after a little guidance. I know very little about email standards such as POP3, IMAP, SMTP which is probably what's making the getting started difficult.
What'd I'd like to do consists of a couple of things:
Be notified of the arrival of an email at a specific custom address. e.g. hi.me#myapp.com.
Handle multiple addresses per user.
Be able to process this email and either delete it, leave it and be able to display in a web email client or forward it on based on various rules.
I've seen a few SMTP libraries and a POP3 one, but I'm not 100% sure what I need to do this. I'm guessing the best way would be to write a full C# mail server - but I'm hoping for a little guidance/suggestion.
Thanks
If you really want to build a mailserver from scratch, the protocol specifications are all available as RFCs.
For IMAP that would be RFC-3501 and for SMTP RFC-2821, you can google for the rest.
I've been working on a C# SMTP server in my (very limited) spare time, mostly out of frustration with existing MTAs and as an exercise in C# server programming. I can tell you that there's a bit more to it than you might think. So if you want fast results, I'd seriously consider hooking into an existing MTA/mailserver setup.
Depending on how fast you want to process messages, it may be sufficient to poll one or more mailboxes. You could process the messages and, for example, forward them to another mailbox using the built-in .NET SmtpClient.
On top of that, all mail servers I know of implement not just the SMTP protocol but also a slew of anti-spam measures. Most of these measures have matured over many years. You get all that for free if you build on top of an existing mail server infrastructure.
Then again, configuration of just about any mail server I know seems to be a fine art, hence my frustration with them.
Problem steps :
My company sends mail to external partners (using .Net SmtpClient),
Some of them have set up "transparent forwarding" on our mails to some of their co-workers,
Those co-workers receive our mails as if we have send them directly to them (no "on behalf of", no classical "forward" from the original "To" mailbox), without any clue of which mail box has transparently forwarded them the mail.
(In fact, smtp conversation traces in the mail properties allows to find it, but most users are not tech savvy enough to be able to access such information, and we have not the knowledge for explaining them how to do for all the varieties of mail clients our partners may use),
Some of those co-workers complains to us that we are spamming them. And if their are unable to transmit us the offending mail untouched (usually as an attachment, preserving the smtp conversation traces), we are helpless in determining by which way they have got our mailing which was not originally directed to them.
Is there a way using SmtpClient to set-up some properties which forbids "transparent forwarding" ?
I do not want to forbid normal forwarding or copying as in How do I prevent Lotus Notes users from forwarding or copying a message sent via System.Net.Mail? question.
I just do want to forbid that "transparent forwarding" (which is IMHO a very bad feature of some mail systems like MS Exchange, which in its rules options gives two way of forwarding, one being "transparent").
As this feature looks to me as being not compliant to smtp RFC, I really fear the answer is no or almost no.
But if your are aware of some custom header for forbidding this on some of those mail systems who do offer that transparent forwarding feature, it may still be of some help to me if their are settable using SmtpClient.
If you are trying to solve the problem of not knowing who the original recipient of the message is, then try adding a line in the body of the message something like this...
"This message was intended for (insert recipient here)."
You can make it visible so the user can see who the original recipient was, or (if you can) put it in super small font so you can use it for troubleshooting/spam claim illustration purposes.
I have an application with a static class that is capturing all errors that happens during the runtime (if its the case) and when process is done, it sends out an email with the list of errors so I or any other developers can address those errors.
However my problem is that McAfee is blocking the request, as if it was a kind of virus. I do not have rights on my machine to edit McAfee settings, is it possible to fix it through C# code?
Thank you
Probably McAfee is blocking outgoing connections on port 25 (SMTP), only allowing a white list of applications to send email.
What you can do is:
Put the email in a mailto:// url. Execute the mailto:// as if it is a normal command line. This will ask for input from the user, but you can create a nice template for the user. (syntax)
Send the email through your normal email client (Outlook, Notes), if they have an API for that.
Use a Http/Web based provider that has an API. Public ones are probably also blocked by McAfee. But you could create & host a service yourself. Be very carefull to only allow traffic from within your company.
Maybe you company has a "drop folder", where you can drop emails that are picked up by the email server.
Depending on what/why McAfee is flagging it, more than likely you will not be able to get around it.
You will want to see if you can find out if McAfee is flagging it due to the port being used, or if there is any other information as to why the individual message is not going.
No. And yes.
No, you can't force McAffee to not flag your email from code, if that's what you mean.
Yes, you can prevent McAffee or other virus scanners from flagging your emails as suspicious. Here are a couple of things I try to make sure of:
That your all addresses (especially from: and reply-to:) are valid.
That the the name you're sending from is actually the name of a the correct person in your active directory.
You could also ask your system administrators to put your "from:" address on a global whitelist so that it always goes to the client.
Are you attaching executables? Are you sure you aren't attaching any viruses? ;-)
From what I recall, I think McAfee has a list of programmes that are allowed to send emails, if your program is not added to this list, then your emails will not get sent.
This is a big support problem, as you will find your customers have a 101 different virus checkers all setup in different ways.
You may be able to setup a email server to use a none standard port, then send emails to that port.
For testing, attaching to the McAfee process with a debugger and then killing it can work well...
As part of my app's config process, I have a sanity checker that validates all user-supplied data. This includes email server settings that the app uses to send email.
I'd like a simple sanity check on those settings without actually sending any email. It'd be great if this could support all standard flavors of SMTP setups including those with authentication/ssl/etc.
It doesn't need to be exhaustive but the more coverage, the better.
Currently all I do is verify I can open a connection to the given server on the given port. Something a little deeper would be nice.
Note: I'm not trying to validate email addresses--that's not relevant to this question.
You just open a raw connection to the server & port that the user supplies and do a
HELO Server.Domain.Com
Mail From: validaccount#domain.com
to see if you get a valid HELO response & Sender OK Response
(if smtp authentication is enabled).
Same as you would do if you telnet direct to the server.
http://www.petri.co.il/test_smtp_service.htm
This might also be useful
http://qmail.jms1.net/test-auth.shtml
I'm sure someone brighter and more qualified will pipe up with a better answer. However, at first blush I'd say that you cannot verify the ability to successfully send email without actually sending an email.
However, if you want to automate the process, you can have a 'MyApp_SanityCheck#gmail.com' (or your local domain) address.
Then you can create a watchdog application that monitors that email address, or just a simple app which programmatically interfaces with that email address and checks if an email was received within X minutes. This way you can be 100% certain that the emails are able to be sent out.
This link shows how to programmatically check gmail addresses.
An important note: If you application is sending out external emails, then it would be best if the email address you use is external, because it is possible that your server could be unable to send external emails, but internal emails go through just fine, and in that case your sanity check would send up a false positive.