From ronsueboe on Wed, 22 Sep 1999
Using Red Hat 5.2 and S.u.S.E. 6.1 I have suddenly run into the same problem. Very terse email relpy's go-mostly. Longer ones don't. Receiving doesn't seem to be an issue. Sendmail is activated but all my emailing is thru Netscape on a dial-up connection and I boot the machine anytime I need to use it otherwise it's off. I tried to disable Sendmailbut this doesn't seem to help.
Any ideas? One more thing. Under RedHat the first message usually would go but nothing after it though it was not hard and fast.
Any ideas? Ron
I'm not sure I understand the whole question. It sounds like you receive mail just fine, but you have intermittent problems sending mail. You think it might be related to the message size. You use use Netscape (Communicator, presumably) to send your mail. You think 'sendmail' might be involved.
I think Communicator tries to send mail directly (looking up your recipient's host MX record and attempting to connect to its SMTP port). It may be that you have it configured to connect to your localhost, or it might "fall back" to relaying through your localhost MTA (sendmail) when it sees a message of a given size, or when it can't connect directly to the appropriate recipient system.
Run the 'mailq' command to see if they are landing in your local mail queue (sendmail). If so, trying connecting to your ISP and running a few copies of 'sendmail -q &' (you can run several of these in the background so that their MX lookups and TCP converstations will occur in parallel). Then you might want to reconfigure NS Communicator to relay your mail through your ISP mail host (often the same one from which you fetch your mail --- your POP or IMAP server).
If not, you might want to look at your /var/log/messages more closely --- to see if your mail is going through there. You could also run 'tcpdump' to watch the traffic on your PPP (or other TCP/IP) line, and see if the traffic is going through your interface at all.
Personally I don't use GUI mailers. I also don't like it when an MUA (user agent) tries to perform transport services (the job of an MTA). I prefer to be able to configure system and site policies on host and network wide bases. So the MTA can do masquerading (making my "From" addresses conform to reasonable patterns), and routing (through my firewalls, etc). Of course this is the bias of a professional sysadmin who works with large sites. For an individual home user it's really about the same either way (though often easier to play with the GUI MUA than to configure your MTA).
(If 'sendmail -q' does help --- you may want to add it to your PPP 'ip-up' script, so a queue run is performed every time you bring up your ISP link).
I hope that works out. You might want to try some tests with 'elm' or some other simple MUA as part of your troubleshooting --- if the 'mailq' and 'sendmail -q' commands don't do the trick.