Help needed with profile picture post--want to replace Sheba the Cat with Frank Shorter

"The following message to a href="mailto:MitziHumph220@rrrc.org">MitziHumph220@rrrc.org> was
undeliverable.
The reason for the problem:
5.1.0 - Unknown address error
550-'sorry, no mailbox here by that name (#5.1.1)'."

I've been trying to replace my profile picture (Sheba the cat inadvertently uploaded) with an old photo I recently found of me with Frank Shorter in 2000. I successfully, I think, did that, but it showed up sideways. 

Then I tried emailing to the suggested rrrc address and received the above message.

Does anyone know how to correct these errors? If not, I guess we'll remain sideways for a while, just as Sheba lingered longer on the message board than I intended.

Thanks to anyone who can figure this out,

Mitzi