I suddenly cannot receive email from a single contact

Starting a few weeks ago I ave been unable to receive email from one of my coworkers. He uses gmail. In the past I have had issues with gmail - the emails from coworkers would be delayed for hours. Usually showing up in bunches the middle of the night. But nothing from the guy.

I will receive replies from others in the thread with his email in the CC box. I use filters to sort my mail but no active filters send mail to trash or delete them. I have my own gmail account and thought a workaround was for him to bcc me on gmail and I would forward the emails to my iCloud. They do not show up either.

I am able the receive emails from all other coworkers using gmail. During the past 2 weeks 2 emails have come through in a timely manner and we THINK they were sent on his android phone (as I write this I am trying to contact him to send me a test email from his phone.)

It is frustrating as our work requires us to be in constant contact via email with multiple parties and using two emails addresses in two separate mail programs is not helpful.

I do not wish to add the gmail account to my macmail as I use it for a professional four which sends out dozens of emails a day and I do not want that on my hard drive. Also the filters send work emails to an iCloud based mailbox and I do not believe I can filter the gmail to that mailbox.

thanks!

Robert