emails works on my local network, but not when I'm away

Apple Mail on Sonoma 14.5. e-mail Pro OVH.
When I am on my local network via smtp.free.fr, I can send and receive emails.
Whenever I'm away, I can always receive emails, but I can't send any, or even reply to an email, even via the OVH SMTP (proX.mail.ovh.net)
I've tried connecting to the Internet via the hotel network or via my iPhone as a shared connection, but it doesn't work. However, with my xxx@me.com email, no problem, everything works.

Any idea to help me?

Thanks

Stéphane