Returned mail virtual alias table

I am getting returned emails. Some people can send me emails and others are having issues. In one case, with people in the same company, some can email, others get their mail kicked back with a message like the below. Anything I can check? I am also seeing email in the log, that is not in my inbox.

Running up to date VM Pro.

Hi. This is the qmail-send program at yahoo.com.
I’m afraid I wasn’t able to deliver your message to the following addresses.
This is a permanent error; I’ve given up. Sorry it didn’t work out.

< edited email>:
xxx.xxx.xxx.xxx does not like recipient.
Remote host said: 550 5.1.1 < edited email>: Recipient address rejected: User unknown in virtual alias table
Giving up on xxx.xxx.xxx.xxx

Look in your mail logs for postfix it will be in /var/log/mail.log for debian or ubuntu. For RH variants it might be /var/log/mail.

Try sending an e-mail to people in your company that are having problem getting e-mail, if you get a message such as Recipient address rejected: User unknown in virtual alias table You need to make sure they have an account in Virtualmins, Edit Mail FTP users.

All I have there is statistics and it will not let me see that file. Says couldn’t display “/var/log/mail/statistics”

I’m assuming you are using postfix as your smtp. If you are using Red Hat or CentOS your mail log will be in /var/log/maillog

Do a tail -f /var/log/maillog

If you are using Debian, Ubuntu:

Do a tail -f /var/log/mail.log

what do you see?

Go to http://member.dnsstuff.com/pages/tools.php

Use the Email test tool for users having problems. See what kind of report it provides you.

Getting MX record for mytechdirect.net (from local DNS server, may be cached)… There is no MX record for mytechdirect.net! That’s bad.
Checking for an A record… Got it!

Host Preference IP(s) [Country]
mytechdirect.net 0 edited IP [US] --------------------------------------------------------------------------------

Step 1: Try connecting to the following mailserver:
mytechdirect.net - edited IP

Step 2: If still unsuccessful, queue the E-mail for later delivery.

Trying to connect to all mailservers:

mytechdirect.net - edited IP [Successful connect: Got a good response [250 2.1.5 Ok]] (took 0.891 seconds)
NOTE: This tool does NOT attempt to determine if an E-mail address exists!

Host: mytechdirect.net
Preference: 0
IP(s): edited
[Country] [US]

I checked your domain it now has an MX record, that’s good. It normally takes about 24 hours for DNS information to propagate through out the Internet. Also checked if your mail servers has an PTR record. Most mail servers will reject e-mail coming from a mail server without a proper PTR.

Here is the result checking for your PTR:

75.13.160.14 PTR record: adsl-75-13-160-14.dsl.fyvlar.sbcglobal.net. [TTL 7200s] [BAD: No A record]

You need to have your ISP provider to change the current PTR adsl-75-13-160-14.dsl.fyvlar.sbcglobal.net. to something like hostname.mytechdirect.net

I’m assuming that you recently just added the MX and A records for your domain that would explain why looking it up came up with [BAD: No A record].

Have you also verified within Virtualmin user accounts having problems with bounced e-mail do have an account or an alias?

I will contact ATT next week.

I am not sure I explained my problem well enough. I have email accounts, all of which work and receive mail. The problem is, when receiving email from certain external accounts (customers,) the email they send gets sent back with that error I posted originally. There is no rhyme or reason, I can receive email from one person in the office without issue, but another cannot and receives the aforementioned error.

You need to have your ISP provider to change the current PTR adsl-75-13-160-14.dsl.fyvlar.sbcglobal.net. to something like hostname.mytechdirect.net

Any reverse resolution is generally fine (we’ve never bothered to have ours changed). So, no trouble with this one. The only problem would be that many mail servers block (or at least treat as more suspicious) any mail coming from IP addresses that are dynamically assigned to dialup and broadband users.

I am not sure I explained my problem well enough. I have email accounts, all of which work and receive mail. The problem is, when receiving email from certain external accounts (customers,) the email they send gets sent back with that error I posted originally. There is no rhyme or reason, I can receive email from one person in the office without issue, but another cannot and receives the aforementioned error.

Sounds like DNS is wrong on one or more of your authoritative name servers. Mail is probably going to the wrong system sometimes.

Double check to be sure the name servers for the domain are correct, using whois:

whois domain.tld

(Replace domain.tld with the domain causing trouble.)

Look for the name servers, and check to be sure all of them respond with the correct address for your mail server using the host command:

host domain.tld name.server.address

For example:

[joe@delilah webmin]$ whois virtualmin.com

Domain servers in listed order:
NS0.VIRTUALMIN.COM 70.86.4.226
NS1.VIRTUALMIN.COM 70.85.191.202

[joe@delilah webmin]$ host -t mx virtualmin.com 70.86.4.226

virtualmin.com mail is handled by 5 mail.virtualmin.com.
[joe@delilah webmin]$ host -t mx virtualmin.com 70.85.191.202

virtualmin.com mail is handled by 5 mail.virtualmin.com.
[joe@delilah webmin]$ host mail.virtualmin.com 70.86.4.226

mail.virtualmin.com has address 70.86.4.226
[joe@delilah webmin]$ host mail.virtualmin.com 70.85.191.202

mail.virtualmin.com has address 70.86.4.226

That’s the full set of data that you need to check–first using whois to know what name servers are being used, then to see if the MX records are correct, and finally to see that the names the MX records point to are actually resolving to the correct system. Any one of those being incorrect could lead to the behavior you’ve described, so I’m pretty sure that at least one of your DNS servers is serving incorrect data.

And, as jaldeguer mentioned, DNS can take several hours to propogate–when making changes, you can never be absolutely sure that all clients have the most recent data…it usually doesn’t take longer than 8 hours, but if the user has a particularly crappy ISP, it theoretically could.

Guys, the error he is getting, which he has clearly provided in the original posting, is "Recipient address rejected: User unknown in virtual alias table".

Wouldn’t it be better to explain how to rebuild the virtual user tables on Postfix, then get sidetracked on DNS resolution issues, which may be unrelated? The delivering mail server obviously found the domain, but his server responded with it not being able to find the user listed in the virtual user table.

Incidentally, I’m getting the same error.

How do you rebuild the virtual user table on postfix?