Can't connect p05-smtp.mail.me.com

System:

MacBook Pro (Retina, Mid 2012)

OS X 10.9.1 (13B42)

Version 7.1 (1827)

I just began using Comcast as my ISP. With this change (and new DOCSIS 3.0 router), Mail can't connect my @me.com / @iCloud.com accounts with server p05-smtp.mail.me.com although all my other accounts (Yahoo, Gmail, Comcast) work normally and can be individually added and modified. When I view Mail / Permissions / Account / Information, these items are grayed-out:

Email Address: Username@me.com or @icloud.com

Full Name: Variable Name

Incoming Mail Server: p05-smtp.mail.me.com

User Name: Username (w/o @me.com or @icloud.com)

Password: (blank but can be added temporarily)

Not grayed out is:

Outgoing Mail Server (SMTP): me.com (iCloud, Offline)

This item CAN be selected and I can

Edit the SMTP Server List . . .

BUT me.com (iCloud, Offline) does NOT appear on the list and thus can not be altered.

I can add a smtp.mail.me.com server with Port 465 (and SSL checked), however, this server disappears, and everything on the account returns to as before, after saving the changes. I can not use Port 587 as Port 587 is restricted by my router (and may not be viable in any regard).

At other times, I receive these two error messages:

Cannot send message using the server me.com (iCloud)

Connections to the server “p05-smtp.mail.me.com” on the default ports timed out.

Select a different outgoing mail server from the list below or click Try Later to leave the message in your Outbox until it can be sent.

"This Mac can't connect to iCloud because of a problem with Username@me.com"

I then open iCloud preferences to fix this problem, but, iCloud preferences only lets me change the description of the account or select or deselect Mail as part of iCloud. I have deselected Mail, and reselected it so that it rebilds, but this doesn't help the underlying problem of sending @me / @iCloud emails.

I've also removed "me.com / iCloud IMAP" account (using "-" from the Accounts page), then added it back using "Mail / Add Account..." but this does not resolve the problem either. The Connection Doctor (Mail / Window / Connection Doctor) variously indicates "red" or "green" about @icloud IMAP connecting.

I've spent several days researching and attempting all manner of options (including deleting a few library folders following one recommendation) but nothing seems to work. Can anyone help, please? Thank you!