Nick,

As this seems related to my issues, I tried your same settings. After setting up webconfig and testing, the reply was "Send failed."

Not much info...

Thanks,
Drew VS

You can even have gmail and outlook365 together. Google "smtp_sender_dependent_authentication" for various reference. Postfix's documentation is here - scroll down to the "Configuring Sender-Dependent SASL authentication" section. What it does not say is that is that you can have a catch-all at the end. I have in my /etc/postfix/relayhost_map file something like:

user1@gmail.com	[smtp.gmail.com]:587

user2@another_isp.com	[smtp.gmail.com]:587

*				[smtp.ntlworld.com]:25

Although I am not sure if the catch-all is needed if you have a "relayhost" defined as well as I think this will be used by default.

There are plenty of other references.

Hi Nick,

Thanks a million for your answer cause i finally solve the issue for both Office365 and gmail.com

Here what I've done to manage it.

edit /etc/postfix/main.cf and add the following lines at the end of the file

relayhost = [smtp.office365.com]:587
smtp_use_tls = yes
smtp_sasl_auth_enable = yes
smtp_sasl_password_maps = hash:/etc/postfix/sasl_passwd
smtp_tls_CAfile = /etc/ssl/certs/ca-bundle.crt
smtp_sasl_security_options = noanonymous
smtp_sasl_tls_security_options = noanonymous

edit /etc/postfix/sasl_passwd and add the following parameter

[smtp.office365.com]:587 mycredential@domain.com:mystrongpasswd

then a few commands to apply configuration and secure the pwd
postmap /etc/postfix/sasl_passwd
chown rootostfix /etc/postfix/sasl_passwd*
chmod 640 /etc/postfix/sasl_passwd*
systemctl reload postfix

and finally back to webconfig:

System > Settings > Email parameters
SMTP Hostname / IP: localhost
Port SMTP: 25
Encryption: none
user SMTP: -> leave field empty !!
password SMTP: -> leave field empty !!
sender email: mycontact@domain.com


It works both with office 365 and gmail account. juste replace smtp.office365.com with smtp.gmail.com


Hope it helps the community...

All my best

I can't get mine to work with GMail either. It works directly to me through my own mail server. As a workround, you may be able to use this document to configure postfix, and then in the Settings app for your SMTP Hostname/IP, set it to 127.0.0.1 or whatever your server name is and use port 25 without authentication. Postfix should then look after the relaying to outlook365. Your Sender Address will almost certainly have to be your outlook365 e-mail addres for this to work.