Don’t use “Outlook (new)” in #Windows 11. I just did a tcpdump and looked also at my #mail servers when setting up an account in there. The mail client only spoke with Microsoft-servers, never with my mail-servers and I saw on my mail-servers only connections from Microsoft-IPs.
@nielsk Century Link requires ISP users to use their outgoing e-mail server so they can monitor your traffic and content. They allow other incoming e-email servers. AT&T is worse. They limit what domain names users can send or receive through their e-mail servers. I can't send or receive e-mail rom my own domain name and Website host. I have to wait for when wifi is available.
@wsrphoto @nielsk Blocking outbound port 25 is pretty common, since a lot of spam originates from infected end-user computers. Use the submission (587) or SMTPS (465) port when sending mail, those should be open (because they only work with encryption and authentication).
@jernej__s @nielsk Thanks. Century Link monitors users' volume, domain names and content on all ports. Twice I've had my account locked because of another user sent spam with my e-mail address. It took a week to get them to check and correct things, and unlock my account. Except for cable there are no options for companies since they have monopoly as telephone service provider.