And we all find ways to deal with it - but it seems that every email server has its own twisted way of making sure the right email never gets to you.
For instance, mine (and I didn't know that), did an email check on the sender - if the sender email is invalid, the email doesn't get through.
Alrighty! That should be cool, right? Well, not really... Because being afraid of spam, a lot of users purposely obfuscate their email address - and I don't get their email. Oh well - lets say we forget that, and move on... But wait, there's more! Even legitimate users, with legitimate emails can get into trouble:
Email verification can be used by spammers, to see if an email exists or not. Now, ain't that cute? Sooo... some email servers decided to get smart, and not respond to email verification. Sounds pretty reasonable, right?
Now, lets see how a server that requests an email verification of the sender plays along with a server that does not respond to it. Well - not good at all: the former server tries several times, and the latter thinks it's spam. End result: an email coming from the latter server will never get through. Aaaaand: you (your ip, email, etc) will end up in the latter server's spam list.
That's what happened to an email I got from Charles Brockman - anyway, I think that's sorted out (even though I'm still on AT&T's spam list :P )
I had my email provider remove that sender email verification for my address. And just when I though I was out of problems, here's an email I got, when answering to someone else:
SMTP error from remote mail server after RCPT TO:<[...]@users.sf.net>:
host mail.sourceforge.net [188.8.131.52]: 550-Postmaster verification failed while checking [...]@torjo.com
550-Sent: RCPT TO:postmaster -at- torjo.com
550-Response: 550 No such email address
550-Several RFCs state that you are required to have a postmaster
550-mailbox for each mail domain. This host does not accept mail
550-from domains whose servers reject the postmaster address.
550 Sender verify failed
Oh well - back to the drawing board - I've emailed my provider - I'll get that "installed".