MO works much better when questions are posted by people who are personally invested in them and are willing to watch and vote on the answers, respond to comments, make clarifications, etc. Also, the reputation system tracks who asks good questions and who does not, which breaks down if one person is posting on behalf of many others.
So I would suggest that you not post other people's questions wholesale. Instead, you could tell them about the site and encourage them to come and post for themselves.
If there are questions, originated by others, that you are personally interested in, and they don't care to post them for themselves, then by all means you should post them yourself. But in this case you should follow the question as if it is your own.
That's my ε dollars.
]]>By the way, there is also the group theory mailing list group-pub-forum, maintained by the mathematics department of Bath University, which usually attracts a high quality of questions and answers, and many of those would really be a welcome addition to MO. It might make sense to point out the existence of MO to the users of that mailing list.
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