Email address keeps kicking back

I have a member whose email address CAN be emailed from my personal Gmail account without issue. His address (I'll mask his real email for privacy) is bra??614@gmail.com. I get this error code when using "Send a Message" to him:

Your message has been sent.

The recipients below were rejected by the server. Please verify their email addresses.

LAST NAME, FIRST NAME (bra??614@gmail.com)

What do I do? It is his email; it works just fine for him and for me.

I've seen this issue with both Hotmail and Gmail accounts. It seems the church's messaging system is unable to send to these domains. It would be great to know why this is the case or if there will ever be a fix for the issue. Perhaps these email services have blocked church servers because too many users have marked such bulk distributions as "junk"?

For messages that cannot be delivered using the Send a Message app in Leader and Clerk Resources (LCR) but have no problem when sent from personal messaging services may be attributed to a setting in the member's Church account profile. This can be verified by seeing if the Local Leader Email setting in the members Church account is unchecked. That setting is found in the Personal : Subscriptions section.

If that setting is checked in their Church account then there is a block for the Church email address and/or domain with the member's email provider. The member can check with their email provider to see if the block is a general block to the Church email address or if it is specific to the member's email account. If it is specific to the member's email account then the member can have it removed. I had the general block removed back in January by putting the Church email address and domain on my whitelist with Yahoo. I don't know if that will work with other email providers.