Quoting Greg Freemyer
All,
I have found with my ISP that I have to have the postfix relay host set to
[mail.atl.bellsouth.net]
Using
mail.atl.bellsouth.net
results in rejected e-mail.
I have no idea why this is true. The fix was provided on my local LUG list.
Maybe this will help out someone else.
PS: if this is a generic issue, maybe yast2 could be modified to add the [] chars automatically. Or maybe it does and I tried to set things manually. I've forgotten.
Greg
RTFM, especially for something as complex as an MTA. [mail.atl.bellsouth.net] says to use this address as is, without doing a lookup for the MX (Mail eXchanger) record. This is usually what you want for an outgoing smart relay host. But not always. mail.atl.bellsouth.net without the brackets indicates lookup the MX for this address and use it instead. This is usually what you want for sending or relaying mail to somewhere. Either RTFM or set your e-mail client to go directly to your ISP's SMTP and POP/IMAP servers, bypassing Postfix. O'Reilly has an excellent book out entitled "Postfix". SAMS also has one out, not as good. IIRC, No Starch Press has one now out or out shortly. The Postfix docs alone are not really adequate. Jeffrey