SMTP problem from e-mail adress out of my domain

Hello everyone,

I’m New here and im facing an issue with my nextcloud mail sending.

I have an owncloud server who is connected to my smtp server who is connected to office 365.

When i try the e-mail test on the admin center it works, when i send a welcome mail to an e-mail on my domain it works too, but when i to send a e-mail to an address who is out my domain thé nothing happen.

Can someone Help me please ? Thank you

You can try to find it out by doing a

tail -f /var/log/mail.log

while sending an email.