I'm a bit baffled by this problem. Maybe there's a sendmail guru out there who can help me out here. We have some end-users who need to receive system-generated mail that originates from a java-based application on our network. The java app sends the mail through our sendmail cluster, which then sends the email on to the end-user over the Internet. The size of the emails can range from a few kb up through around 2Mb in size. The mail logs show that these emails are typically delayed for up to 24 hours, sometimes longer. It appears that several attempts to deliver the email are made, with each unsuccessful one showing "Deferred" status in the maillog. After several hours of failed attempts the mail finally goes through successfully. Here is a typical entry (customer name redacted): exmx1 : Dec 14 05:28:39 exmx1 sendmail[31574]: mBDIYhEa031574: to=< customer at example.com>, delay=00:00:00, xde lay=00:00:00, mailer=esmtp, pri=41874, relay=mail.example.com., dsn=4.0.0, stat=Deferred Unfortunately there is no reason given for the "Deferred" status such as "Server unavailable", etc. Do you have any ideas how I can begin to troubleshoot this? -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.centos.org/pipermail/centos/attachments/20081215/b5f35a16/attachment-0003.html>
"I'm a bit baffled by this problem. Maybe there's a sendmail guru out there who can help me out here. We have some end-users who need to receive system-generated mail that originates from a java-based application on our network. The java app sends the mail through our sendmail cluster, which then sends the email on to the end-user over the Internet. The size of the emails can range from a few kb up through around 2Mb in size." I should probably add that each of these emails has an attached file, which accounts for the large size of the emails. Also, sorry if my previous email was sent in HTML format, I think I might have had "rich text" turned on in Gmail.
Sean Carolan wrote on Mon, 15 Dec 2008 10:15:15 -0600:> Do you have any ideas how I can begin to troubleshoot this?sendmail -v -q (will flush the mail queue, just wait and look). First reason I would think of: greylisting. Kai -- Kai Sch?tzl, Berlin, Germany Get your web at Conactive Internet Services: http://www.conactive.com
On Mon, Dec 15, 2008 at 10:15:15AM -0600, Sean Carolan wrote:> exmx1 : Dec 14 05:28:39 exmx1 sendmail[31574]: mBDIYhEa031574: to=< > customer at example.com>, delay=00:00:00, xde > lay=00:00:00, mailer=esmtp, pri=41874, relay=mail.example.com., dsn=4.0.0, > stat=Deferred > > Unfortunately there is no reason given for the "Deferred" status such as > "Server unavailable", etc. > > Do you have any ideas how I can begin to troubleshoot this?Hi Sean, Two suggestions, #1 - turn your sendmail logging/debugging setting up as high as it will go for just long enough to capture some of these events. (then turn it back to its previous setting) #2 - try using script and then telnet to capture an SMTP session (Done by hand) with the MTA at the receiving end. This can be a little tricky and requires a good understanding of how SMTP transactions are done so you can emulate it by hand. I would focus on hat the receiving end does when you send it a length that is > 1 MB. Jeff Kinz
> #1 - turn your sendmail logging/debugging setting up as high as > it will go for just long enough to capture some of these events. > (then turn it back to its previous setting) > > #2 - try using script and then telnet to capture an SMTP session > (Done by hand) with the MTA at the receiving end. This can be a > little tricky and requires a good understanding of how SMTP > transactions are done so you can emulate it by hand.Thank you all for the suggestions, I think we may have pinned down the problem. This list is a great resource, props to all the experienced users who put in time answering questions here. :)
==================================== The mail logs show that these emails are typically delayed for up to 24 hours, sometimes longer. It appears that several attempts to deliver the email are made, with each unsuccessful one showing "Deferred" status in the maillog. After several hours of failed attempts the mail finally goes through successfully. Here is a typical entry (customer name redacted): exmx1 : Dec 14 05:28:39 exmx1 sendmail[31574]: mBDIYhEa031574: to=<customer at example.com>, delay=00:00:00, xde lay=00:00:00, mailer=esmtp, pri=41874, relay=mail.example.com., dsn=4.0.0, stat=Deferred Unfortunately there is no reason given for the "Deferred" status such as "Server unavailable", etc. ===================================I would imagine this is a hotmail or yahoo account or something along those lines. Deferred does not usually mean bounced or turned into spam, it is more of a way of making the user wait for their mail. Yahoo can hold mail for a long time, minutes to hours, before they deliver. If you keep resending the deferred mail, you may end up getting auto junked though. In my minds eye, they are just trying to get people to upgrade as then as if by magic, mail to them does not get deferred. But in my experience, all deferred mail is usually sent, as far as I know. Just 'deferred' for a bit.
on 12-15-2008 8:15 AM Sean Carolan spake the following:> I'm a bit baffled by this problem. Maybe there's a sendmail guru out > there who can help me out here. We have some end-users who need to > receive system-generated mail that originates from a java-based > application on our network. The java app sends the mail through our > sendmail cluster, which then sends the email on to the end-user over the > Internet. The size of the emails can range from a few kb up through > around 2Mb in size. > > The mail logs show that these emails are typically delayed for up to 24 > hours, sometimes longer. It appears that several attempts to deliver > the email are made, with each unsuccessful one showing "Deferred" status > in the maillog. After several hours of failed attempts the mail finally > goes through successfully. Here is a typical entry (customer name > redacted): > > exmx1 : Dec 14 05:28:39 exmx1 sendmail[31574]: mBDIYhEa031574: > to=<customer at example.com > <mailto:customer at example.com>>, > delay=00:00:00, xde > lay=00:00:00, mailer=esmtp, pri=41874, relay=mail.example.com > <http://mail.example.com>., dsn=4.0.0, stat=Deferred > > Unfortunately there is no reason given for the "Deferred" status such as > "Server unavailable", etc. > > Do you have any ideas how I can begin to troubleshoot this? >Does the machine have good dns resolution? Are the clocks synced to a proper time.. (IE... local time is +8 but the clock is actually -8). GMT is OK as long as the box knows that is its timezone. -- MailScanner is like deodorant... You hope everybody uses it, and you notice quickly if they don't!!!! -------------- next part -------------- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 250 bytes Desc: OpenPGP digital signature URL: <http://lists.centos.org/pipermail/centos/attachments/20081215/9f55f7e0/attachment-0003.sig>