What does appear in the log? Is DNS fast and reliable? Check every name server in resolv.conf to be sure it resolves the destination quickly. Mail performance is very DNS dependent, as it a lot of spam-related stuff is running over DNS. Also make sure your DNS servers are fast, and any DKIM/SPF related stuff responds quickly.
In addition to the excellent suggestions made by @Joe, you could also check if you have virus and spam scanning configured to check outgoing email. If so, this could account for the delay.
All domains are hosted in Cloudflare and the required records point to the server’s IPs.
Pinging domeniu.com [x.x.x.x] with 32 bytes of data:
Reply from x.x.x.x: bytes=32 time=133ms TTL=44
Ping statistics for x.x.x.x:
Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
Minimum = 132ms, Maximum = 134ms, Average = 133ms
Scanning outgoing mail does not happen by default. I’m not even sure how one would implement that (it’s possible, but nothing we provide makes it easy…you didn’t accidentally turn it on, I’m pretty sure).
There is no setting! It’s not a thing. I don’t know how to be more clear. Virtualmin does not have any implementation of scanning outgoing email.
It can’t be your problem, because it doesn’t exist (unless you set it up yourself outside of Virtualmin, but since you have no idea what it is or how it’s done, we can be confident you didn’t do that). So, stop fixating on this; scanning outgoing mail is not your problem. It cannot be.
@Joe is correct. I am sorry to have caused this confusion when I was attempting to point out that your outgoing email @cipandales could be delayed due to virus and spam scanning configurations (that you may have set up, as I have in deviation to default Virtualmin) to check outgoing email.
On my system it causes exactly the sort of delay you described so in my rush to point this out, I appear to have harmed more than helped. Sorry again, please disregard my earlier comment.
That comma is funny. Shouldn’t be there. Just use whitespace between long and short names. And, it should be flipped.
e.g.
192.168.1.1 myhost.domain.tld myhost
When you run hostname -f it should return a fully qualified domain name. If it doesn’t, /etc/hosts is wrong and should be fixed, as it will cause mail problems among other things.