My 2012 MBP that I'm using to write this piped up to disagree. It retrieves mail from a variety of sources every day, including work email, and there is never a problem. All using the stock Mail app that comes with the OS. So I'm guessing some details are being mis-remembered by the 2nd-hand information supplied by a person who doesn't sound technically-inclined enough to have gotten the story right in the first place.

IOW, if one is to supplied anecdotal data, probably best to make sure it's your anecdote, maybe?