How can you make sure your users are actually getting your emails?
Sending email in code might seem easy, especially in .NET. But because of the prevalence of spam, there’s a lot of hoops legitimate senders need to jump through to give their users a fair chance of actually receiving their emails.
You’ll want to set up a few things that your recipients’ email servers check to verify the email they receive from you. Check out this intro from Jeff Atwood.
Then these tools will help:
MX Toolbox – Check DNS server records.
Adding DKIM Records to Windows Server – Proving your emails came from you.
Checking Your DKIM Records – Make sure you did it right.
Checking Your SPF records – One more way to verify emails.
Test Email Signing – Make sure your emails are actually getting signed. You might also try this site.
Now, with regard to the content of your emails; you’ll want to make sure they don’t smell like spam. SpamAssasin has some general tips. You can also have a look at the rules SpamAssasin uses to determine if your email is spam. And this site has a spam score checker you can use.
You can also sign up for email whitelists, such as Trend Micro‘s.
Even if you follow all the rules, there will always be someone with an overly aggressive Outlook junk filter. Hopefully, this all helps, though.