MacMail with Comcast email address, Do not receive all emails that are sent to me. Mac OS Sequoia 15.5

Cannot receive my Lowe's receipts when selecting "send to" my Comcast email address but I do receive them when I select to have them sent to my Gmail address. The pastor of connections at my church also says that he believes that any messages sent to a Comcast email are not received. I used to get the Lowes receipts via Comcast email address but not in the last 3 or 4 years. Have always been successful using MacMail to retrieve my messages.