Q: No "Not Junk" option

Just drag and drop the mail from the Junk folder to your Inbox.

Are you using iCloud mail?

A Me.com is the same thing as an iCloud account. If that is what you are using, you should uncheck the "Enable junk mail filtering," option and just rely on relocating the mail to appropriate baskets.

However, I don't use GMail with Mail, even though I have a GMail account, because GMail uses a nonstandard IMAP implementation, and they mine your data.

this particular behavior is with one of my Gmail accounts.

Check you Gmail account online to see if it has a junk filter turned on.  If not then try creating a Rule like this and see if that will do the trick:

If the e-mails aren't brown/tan, then your e-mail provider may have marked them as junk, which would explain why the not junk option isn't there. Try going to the e-mail provider's website to see if you can adjust the junk settings there.

FrRon wrote:

Identify and filter junk mail in iCloud - Apple Support

You are welcome.