Sending mails from a mail client

Hello.

I am using mailbird as my mail client and added one of the mail accounts from ispconfig to it.
I can receive the mail in the client, but when i try to send a mail i'm getting this error:

Code:

[email protected]: 554 5.7.1 <unknown[xx.xx.xx.xx]>: Client host rejected: Access denied

xx.xx.xx.xx = my pc's ip address

I don't understand where the problem lies.
Is the problem from the mail client, my server, or gmail?
I have attached screenshots of the error and the settings used in the mail client.

 

different servers for send and receive?

 

I only got one server (vps) if that's what you mean.

 

accoding to your screenshots, you are using *.host for in- and *.org for outbound.

you server rejects a mail from @gmail.com - that´s ok.

 

I tried setting both in and out to *.host and *.org, but nothing changed.

I really don't understand what happens.
How does my server rejects a mail from @gmail.com when i try to send to @gmail.com ?

 

This is not an authenticated connection.

 

Yes, i checked the "Require authentication" and added the ispconfig mailbox user and pass and it works, i feel dumb now.

Thank you very much, have a nice day.