at work we have a database with member details incl. email addresses.
on several occassions i have sent a bulk email out based on the email address from our d/base. i always get a reply from one particular person asking me not to email them in the future (in capitals with lots of exclamation marks). Fair enough. however, that person is not a member and we do not have their email address on our d/base.
they reply from my original email ie it is not being forwarded to them and they then reply to me. i've even checked through the bcc field of emails i've sent and they are not there.
That sounds plausible. I have two addresses. When I download my e-mail it says to 'address 1' or to 'address 2' but, using thunderbird, all my out-going e-mail sent from 'address 2'
So if you e-mail me on 'address 1' the reply will be from 'address 2'
Also, yahoo can be set up to retrieve e-mail from other pop e-mail servers.
i suggest you reply to this person, apologise, say that the e-mail addy they are contacting you on is NOT in your database, and please double check the 'to' addy on the e-mail they don't want, as it must be to one of their other addy's, perhaps one they had forgotten about, but their e-mail client still retrievs mail from.