Postfix with SMTP Submission on Port 587

I set up a new box using Virtualmin on CentOS but ran into an issue. I need to turn on the SMTP Submission port on 587. I didn’t see an entry in the control panels, maybe I missed it, so I edited the file by uncommenting the submission line. This worked to turn it on after restarting postfix. The problem is that users get rejected by the username. It will not accept the usual user.domain or even user@domain.tld. Is there a trick I am missing on how to handle that? The smtp auth they are using says to send the same username and password for sending mail.



If it matters, here are the additional configs I added to help with spam. Perhaps one of them is giving trouble.

smtpd_delay_reject = yes
smtpd_helo_required = yes
smtpd_helo_restrictions =

smtpd_sender_restrictions =

smtpd_recipient_restrictions =

smtpd_client_restrictions =


What are you seeing in the mail logs over in /var/log/maillog? That may offer some details on what’s going awry.

You’ll want to make sure that saslauthd is running, and that it’s using the -r parameter.

Also, you might consider enabling SMTPS in addition to submission, and accessing that on port 465… I’m curious if that happens to work for you.


In /etc/sysconfig/saslauthd, there’s a “FLAGS=” section… try adding the “-r” param to that, so that it looks like this:


And then restart saslauthd with:

/etc/init.d/saslauthd restart

Let us know if that does the trick!


This appears to be from a block where I know I remoted into his machine in an attempt to see what was up:

Jun 22 06:52:51 hosting1 postfix/smtpd[27344]: warning: hostname verification failed: Name or service not known
Jun 22 06:52:51 hosting1 postfix/smtpd[27344]: connect from unknown[]
Jun 22 06:52:52 hosting1 dovecot: pop3-login: Login: user=<mitchc.xxxxxxx>, method=PLAIN, rip=::ffff:, lip=::ffff:
Jun 22 06:52:53 hosting1 dovecot: POP3(mitchc.xxxxxx): Disconnected: Logged out top=0/0, retr=0/0, del=0/0, size=0
Jun 22 06:52:53 hosting1 postfix/smtpd[27344]: NOQUEUE: reject: RCPT from unknown[]: 504 5.5.2 <[Email Confidential]>: Recipient address rejected: need fully-qualified address; to=<[Email Confidential]> proto=ESMTP helo=<[]>
Jun 22 06:52:54 hosting1 postfix/smtpd[27344]: lost connection after RCPT from unknown[]
Jun 22 06:52:54 hosting1 postfix/smtpd[27344]: disconnect from unknown[]
Jun 22 06:53:11 hosting1 postfix/smtpd[26816]: lost connection after DATA from unknown[]
Jun 22 06:53:11 hosting1 postfix/smtpd[26816]: disconnect from unknown[]

As far as the saslauthd :

ps axwww | grep saslauthd
6432 ? S 0:00 sh -c su root -c ps\ axwww\ |\ grep\ saslauthd 2>&1
6433 ? S 0:00 su root -c ps axwww | grep saslauthd
6434 ? S 0:00 bash -c ps axwww | grep saslauthd
6436 ? S 0:00 grep saslauthd
18568 ? Ss 0:00 /usr/sbin/saslauthd -m /var/run/saslauthd -a pam
18569 ? S 0:00 /usr/sbin/saslauthd -m /var/run/saslauthd -a pam
18570 ? S 0:00 /usr/sbin/saslauthd -m /var/run/saslauthd -a pam
18571 ? S 0:00 /usr/sbin/saslauthd -m /var/run/saslauthd -a pam
18572 ? S 0:00 /usr/sbin/saslauthd -m /var/run/saslauthd -a pam

I have not changed anything with saslauthd as I have not learned about this yet.

So, any other ideas why it’s bombing out?


Here are the results:

ps axwww | grep saslauthd
9019 ? Ss 0:00 /usr/sbin/saslauthd -m /var/run/saslauthd -a pam -r
9020 ? S 0:00 /usr/sbin/saslauthd -m /var/run/saslauthd -a pam -r
9021 ? S 0:00 /usr/sbin/saslauthd -m /var/run/saslauthd -a pam -r
9022 ? S 0:00 /usr/sbin/saslauthd -m /var/run/saslauthd -a pam -r
9023 ? S 0:00 /usr/sbin/saslauthd -m /var/run/saslauthd -a pam -r
9043 ? S 0:00 sh -c su root -c ps\ axwww\ |\ grep\ saslauthd 2>&1
9044 ? S 0:00 su root -c ps axwww | grep saslauthd
9045 ? S 0:00 bash -c ps axwww | grep saslauthd
9047 ? S 0:00 grep saslauthd

As far as that message, it seems to be caused by the user making a mistake that I did not initially see. I opened up the email on his machine remotely and saw that he was trying to send the email to an invalid email address and that is what the error message was trying to tell him. From the log this was the clue: “RCPT from unknown[]: 504 5.5.2 <[Email Confidential]>: Recipient…” He clicked on a link to send an email but it put in a corrupt email address. He filled in the remainder of the email and send it on. It was in the log too but I didn’t interpret the log correctly. Anyway, I sent a test message from his computer to mine and it seemed to go through. So, it seems to be resolved and working now.

I appreciate your help and quick response.

Now, to gather my info for another post about graylisting and spf record services. I spent HOURS reading but got no where. Hopefully you’ll have the answer to those as well. :slight_smile: