[SOLVED] Domain of sender address does not exist

iulinux · 08-07-2021, 01:36 AM

I am trying to send an email logged in as root to user@localhost but haven't been successful.

Checking the email log file I see the notification: domain of sender address does not exist.

I can't seem to find a consensus online so far that clearly explains what the issue is and so how to resolve it.

bathory · 08-07-2021, 08:09 AM

Quote:

Originally Posted by iulinux

I am trying to send an email logged in as root to user@localhost but haven't been successful.

Checking the email log file I see the notification: domain of sender address does not exist.

I can't seem to find a consensus online so far that clearly explains what the issue is and so how to resolve it.

You should stick at your other thread with the same problem and not start a new one.

Anyway make sure you have the following in /etc/hosts

Code:

127.0.0.1   localhost localhost.localdomain
::1         localhost localhost.localdomain

iulinux · 08-07-2021, 08:17 AM

Thanks. I'll try that now. Would I need to restart sendmail as well?

bathory · 08-07-2021, 08:27 AM

Quote:

Originally Posted by iulinux

Thanks. I'll try that now. Would I need to restart sendmail as well?

Nope.
But you need to have "files" before "dns" in /etc/nsswitch.conf hosts line, like this:

Code:

hosts:  files dns

iulinux · 08-07-2021, 08:39 AM

Presently I have this inside /etc/hosts

Code:

127.0.0.1       localhost
127.0.0.1       vboxslack.  vboxslack

Am I replacing this whole code with what you sent or do I just include it to this?

bathory · 08-07-2021, 08:52 AM

Quote:

Originally Posted by iulinux

Presently I have this inside /etc/hosts

Code:

127.0.0.1       localhost
127.0.0.1       vboxslack.  vboxslack

Am I replacing this whole code with what you sent or do I just include it to this?

No need to do something. You can leave /etc/hosts as is.

iulinux · 08-07-2021, 09:00 AM

Quote:

Originally Posted by bathory

No need to do something. You can leave /etc/hosts as is.

So my /etc/hosts file was not the issue?

bathory · 08-07-2021, 10:37 AM

Quote:

Originally Posted by iulinux

So my /etc/hosts file was not the issue?

I guess not!

You should know that mail is heavily dependent on dns. If you use the order "files dns" in /etc/nsswitch.conf, then your system will use first /etc/hosts in order to resolve a domain/hostname and if doesn't succeed it will use a dns resolver.

Anyway, did you try to send an email to user@localhost and see what happens. And you can always omit the @localhost part since you're mailing to a local account.

iulinux · 08-07-2021, 10:47 AM

I tried. But no luck.

iulinux · 08-07-2021, 11:17 AM

Domain of sender address root@vboxslack does not exist

Ser Olmy · 08-07-2021, 11:37 AM

Deleted, misread the OP.

iulinux · 08-07-2021, 11:39 AM

It is a local user

bathory · 08-07-2021, 11:59 AM

Quote:

Originally Posted by iulinux

Domain of sender address root@vboxslack does not exist

Run as root:

Code:

mail -s Test user@localhost < /dev/null

and post here the relevant part of maillog

iulinux · 08-07-2021, 12:35 PM

Please see the attached screenshot. I can't copy from my virtual machine

Ser Olmy · 08-07-2021, 12:51 PM

"vboxslack" is the hostname of the VM. sendmail expects a valid FQDN.

What does hostname -d and hostname -s report?