Setting mail client, but cannot receive email

OS type and version Ubuntu Linux 20.04.5
Virtualmin version 7.1-1

Hi there. I setup postfix and dovecot. everything in DNS server is okay. I am able to send message from webmin interface as well as using Mozilla Thunderbird. But when trying to receive email from an external sender I can read received email from webmin but not the client. There is no error message for me to follow. mail.log is also same, no error. I try imap setting with different configs such as changing port and so on. none of them helps. I switch to another client but the results are same.
I wish someone to tell me where to look for? And whatever conf is needed I can provide accordingly since I do not know where to look at this moment.


Are ports 143 and 993 open in the firewall?

yes all needed ports are open. and using telnet is successfully connected

That’s odd.

Is Thunderbird able to retrieve email from other providers using IMAP?

Is Thunderbird allowed network access on the client computer?

Does the mail log show anything at all for the connection attempt?

Is it possible that the client computer’s public IP is being blocked by fail2ban, CSF, or some other login-failure detection application since you connected with Telnet?

Just random ideas. I don’t know enough about Ubuntu to be specific.

Lemme answer one-by-one. yes thunderbird is retrieving email from other providers, and it has network access. Client has static IP and not blacklisted or any of the block such as fail2ban is not listed. And about the logs…
in the logs I can see successful incoming email, dkim is successful and so on, after these logs as I said I can read email from server itself but no client can read it. I try outlook, android`s mail app, too. None of them can receive the email

I suppose it was too obvious to ask, but is Dovecot running?

Having exhausted the obvious, I’ll have to defer to others because I know little about Ubuntu and am not an expert in Postfix. I’m pretty good with Dovecot, but I suspect that the problem is more likely with Postfix.

Specifically, my guess would be that the protocols to allow Dovecot to handle the mail might not be enabled in Postfix ( /etc/postfix/ in RH, not sure where in Ubuntu). But that would just be a guess; and because I prefer not giving advice unless I actually know what I’m talking about, I’ll just hope that someone smarter than I am comes by soon.


Thanks Richard for taking your time and trying to help. Appreciate. I am also in search for the issue. And yes Dovecot is running. :slight_smile:

I wonder if enabling session logging in Thunderbird might help.

What hostname (incoming server / outgoing server) are you using when you configure the client (Thunderbird) to retrieve mail from the Virtualmin? If it is clientdomain.tld, try replacing that with virtualminhostname.tld

I try this, but log is empty.

I set separate domain as mail server. in and all dns records accordingly. mail client connection is not an issue, sending mail is successful, whereas imap is not having any errors and not receiving mails, too.

You appear to have made too many unique customizations to your install of Virtualmin for it to be considered standardized. In this situation, I don’t know if the advice that the community offers, based on an assumption of a standardized install of Virtualmin, would apply to you.

It might be a good idea to hire a Virtualmin consultant like @tpnsolutions to study your system and offer a solution.


I’d be happy to schedule some time to look into your issue further. Either drop me a line here or at to schedule a consultation.

Thanks @calport for bringing this matter to my attention.

*** Quality, Professional, Affordable Virtualmin assistance ***

does usermin or any other webmail on server read incoming email normally?
when you see email from webmin are you logged in as root?
did you check mailbox permissions?

yes it is. I can read mail normally from server itself, as a root or any user.

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