[Whatever]

In Comcast e-mail, how do you go about blocking a sender?

[Uptown Girl]

Don't know if this is the best answer, but you could mark it as spam, or just delete it before opening. If it is from a sales company, you can unsubscribe from receiving their email.
Does that help you?

[batman911]

If you are using MS Outlook, you right click on the email in your In Box. Then select Junk Email, then Add Sender to Blocked Senders List.