Port 25

@EG​ My request is not about Comcast email. I use office365 and need access to their port 25.

Thank you

Your concern is in the proper help section now.

@user_0swnv2 Please accept my most sincere apology for the experience you have encountered. I would recommend attempting to reach out to our Customer Security Assurance team again to see if there is any additional assistance they can provide.

Email is used for important communications and Comcast wants to ensure that these communications are as secure and as private as possible. As such, Comcast does not support port 25 for the transmission of email by our residential Internet customers. The original/legacy email ports, 25 and 110, have been in use since the inception of email and have limited or no security features. As a result, port 25 has been used for the transmission of spam and malware from infected computers for nearly a decade.

If you need port 25, I do not believe we can fully remove that block and is also blocked by a wide variety of other ISPs as well. We also recommend reaching out to Office 365 if you are needing port 25 for a certain program feature or function for any possible workarounds they may know to assist you. 

The Federal Trade Commission, an organization that has taken legal action against many spammers, also recommends that Port 25 should be blocked by ISPs. The FTC’s recommendation is as follows:
"Block port 25 except for the outbound SMTP requirements of authenticated users of mail servers designed for client traffic. Explore implementing Authenticated SMTP on port 587 for clients who must operate outgoing mail servers."

For additional information about Why Port 25 for Email Submission is Not Supported, please see our help article. 

@again, I need services like homeassistant to send email on certain events. I am using office365 and want to use its smtp service.

@user_0swnv2​  When you setup mail use port 587 for smtp submit, like any other mail service.

smtp server = smtp.office365.com

port = 587

requires ssl = yes

requires tls = yes (if available)

authentication = yes

username = Your full microsoft 365 email address --> yourusername (at) yourdomain.com

password = the password associated with your microsoft 365 email address

If your devices cannot send mail using ssl or at least tls encryption (required by just about everyone), then you would need to setup a local mail transfer server (MTA)  that can.  A linux/unix box of some kind and postfix to use an external SMTP emal account is a way to do this.  You can do that in a virtual machine on windows machine you leave on all the time if you have to.  (search for virtualbox)

Local devices send mail to postfix listening locally on your LAN on port 25, then it submits/relays mail on 587 and handles authentication and encryption for you.  There are lots of postfix tutorials.