"Junk mail" from iCloud.com?

Not sure if this is relevant.  I just googled email from I cloud and this was at the top of the list.  Seems any apple user with iOS 7 or earlier can send email from iCloud Mail.

iPhone, iPad, or iPod touch

Go to Settings > iCloud. In iOS 7 or earlier, tap Settings > iCloud > Account.
Tap Mail under Advanced.
Under iCloud Account Information, tap your email address.
Tap the @icloud.com email address that you want to use as the default for sending mail from iCloud Mail.

Using your @icloud.com email address - Apple Support
https://support.apple.com/en-us/HT201342Apple

and then there was this:

iCloud scammers send fake Apple emails and texts to iPhone owners ...

www.dailymail.co.uk/.../Beware-Apple-iCloud-scammers-Cri...

Daily Mail

Sep 2, 2014 - Beware the iCloud scammers: Criminals take advantage of leak by ... 'In addition to email scams, some users may be the recipients of a text ...

I'm not sure if this is helpful or not, but I just checked and all of my no reply emails from email.apple.com came from "no_reply" rather than from "noreply" (the difference being the underscore). All my emails specifically regarding the iCloud service have the word "iCloud" as part of the email address.

Some email filters don't discriminate between addresses with and without dots, dashes and underscores prior to the "@" symbol, and some filters do discriminate between them. If I were in your shoes, I'd create a filter for the offending emails and then just keep an eye on it to see if it is also accidentally weeding out the legitimate emails. Just don't empty your trash until you know for sure.

I realize this will take awhile and it's not a very elegant solution, but I don't know what else you could do from the recipient side.

have no idea if it's related or not but I just got birthday greetings from JML...