Twitter – How ‘Mention’ Spam Works

I would let one account handle the spam filtering for all of your accounts. I don't believe there are many benefits to having each account handle its own spam. I think Gmail is aware of the destination address of each incoming mail and having identical spam emails (with only the destination address changing) will strengthen the spam algorithm just as much as if it were single emails sent to multiple accounts.

Regardless of how much (more) it might improve the spam algorithm, you should choose the solution which best improves your workflow. I would just go with the first option (spam filter on the main account).

FYI: I use Gmail to process email from 12 accounts across 7 domains each with spam being primarily handled by my main Gmail account. :)

My recommendation would be to use both, but if i had to pick one i would say a formal twitter account.

As you yourself noted in your question both the hashtag and account serve two very different purposes but work well together.

The hashtag is a great way to attach a subject to a tweet. Although getting people to use your specific hashtag can be a challenge at times.

A formal twitter account would allow let other twitter users engage with you ( or whomever is running the account ) on a more intimate level. While at the same time letting you broadcast and start conversations with other people.

m