Think i might not have explained myself - my emails come in via my forwarded email to my gmail account. I send them straight from my gmail account, but set the "ReplyTo" to my forwarding addy. They still come directly from my gmail though (and show as that).
Granted - a POP3 account is the best way to do it. I have the two domains (same one, but one is .com, the other.co.uk - long story) and just haven't bothered to change the forwarding one to a proper POP3 account. Should do really - but have never had a lost email (to my knowledge).
A lot of spam filters will still reject mails you send, as the checks against your domain do not authorise the smtp server to send on your behalf.
Thats exactly it - i don't send the mails from my .com incoming-gets-forwarded address, but direct from my gmail account. I have just set the "Reply To" (not the From) address to my .com address. Depending on the email client used at the other end, it may or may not be sent to my forwarding address first.
Wires got crossed (or not forwarded correctly
) here, TB?
Some smtp relays nuke a msg based on FROM:, some nuke based on REPLY-TO:, some even nuke if they are different.
As the spammers get more intelligent - there is a huge amount of money in spam - the mail server operators have to introduce new ways to prevent it, so no hard and fast rules.
Generally, the sending relay's IP needs to resolve in (r)DNS, and needs to be mentioned in the SPF record for the domain specified in FROM: or REPLY-TO: (or both) to make it passed the first stage of the relay (at can be subsequently nuked by other UCE filters beyond that, eg Black/Whitelists, content analysis etc)