For past few days, emails are being spontaneously deleted from my inbox with no action on my part. Some of them I have opened, there may be some I haven't. Where are they going?
How can I retrieve them and stop this from happening??
Most often email disappears from Comcast's "Xfinity Connect" webmail Inbox because an email program (ex: Outlook, Mac Mail) or mobile device (smartphone, tablet) using the POP protocol removes the mail from the server.
Check all mobile devices and email programs on all computers. The missing mail may be in the Inbox of one of these. If you can't find the culprit, change the Comcast password for the affected userID to prevent mail from being removed. You can change your password in "My Account" (https://customer.xfinity.com/#/users) under "Users" / (username) / "Username & Password" / Password / Edit.
Once you identify the offending device or program, change its settings to "Leave a copy on the server", and make sure that a "Delete after xxx days" or similar setting is not active. Or change the protocol for Incoming mail from POP to IMAP. Or, in webmail settings, change the Advanced setting "POP Settings for Other Apps" to "Keep".