Issue 48000 mail queue

[cpartassides]

I navigated today to the mail queue in plesk (using postfix , centos 12.5.30 Update #38 ) and to my horror i found there 48000 spam emails in the queue.
I think that all of them have sender a domain hosted on my server but the specific email account does not exist. Not sure what is going and is freaking me out.
Tried the following
1. see the log of the domain for any calls , but the website is not very busy so nothing was going on in the log
2. changed relaying to closed but i am pretty sure that broke all email

The above did not work so not sure what is going on . Any advice is much appreciated. What have i done so wrong in order to allow my email server to be open to spam sending ?

 

[lvalics]

Check how you can read the messages in queue and then read one message (with same subject), especially the header, then in header try to see which UID sending out. Sometimes you can find the domain UID. This can help to get out which domain generating the emails.

Get the id of the message by
mailq | grep "search something"

Then
postcat -q MESSAGE_ID

 

[cpartassides]

Well , what i did is actually clicked on an email and noticed in the headers the originating script. It seems a word-press installation got infected with some kind of script.

It would be nice in the Outgoing Mail Control even if there aren't any limits in subscriptions to see the total which is sent