Replies fail unless receipt is enabled

[stib]

I can't seem to reply to anything unless I check the message receipt button. I can send new messages, and I can forward messages just fine. It's just replying that I have problems with.

If I set my $rcmail_config['smtp_server'] setting to %h it just stalls, and I can't send or forward any mail, so I leave that blank.

Nothing shows up in the logs, I just get a message saying "sending message failed"

This is on 0.3.1 on a linux server.

Thanks

[rosali]

Check your SMTP server logs.

[stib]

Forgive me for being dim, but where would I find the SMTP logs? I've looked in all the directories in my mail dir, including hidden files, but I can't find any logs except my access log.
-stib