That problem, though mildly annoying to the blog owners affected, has an easy workaround - use a GMail based email address, for comment moderation / notification. That's a quick 15 minute fix.
- Setup a GMail account, if necessary.
- Change the comment moderation / notification email addresses, for the blog(s) affected, to use the GMail email account.
Besides the ease of putting a workaround in place, that problem is not all that severe. The problem with comment moderation / notification email, being filtered, only affects blog owners who moderate before publishing. Owners who moderate after publishing can always use the Blogger dashboard Comments wizard, at their convenience, to moderate.
This week, we realised that the base problem - rejected email because of non GMail based Blogger accounts - may also affect owners of private / team blogs, who have prospective non GMail members. This specific problem probably affects less blogs - but it won't have as easy a workaround.