SMTP Error every time i try to send an email

Hello guys!

I am trying to fix an issue over the control panel of Sentora and tried many times to search for a solution, either online, either in this forum but without any luck. I hope you guys can help me solve this issue.

So i had an account lets say abc.com in server A and then, i deleted that account from Sentora control panel, created a new server B with the account there. Now if i want to send an email from server A to server B to that domain name i get an error on server A saying this:


So as you see i get this error, every time i try to send an email.

Any idea how to fix this issue? Thanks in advance guys, any help is much appreciated!