[entwisi]

you mention its an AOL account. You could try asking their customer support. It all depends on how they have implemented it under the hood. AOL are rekown for doing stuff in non standard ways so you may be lucky, you may not.

An alternative would be to have your own domain with its own SMTP server but again you would need to check that you can use one under AOL. They have a nasty habit of blocking certain ports(Not alone here, Orange do the same although I get round it due to my hosting company supporting SMTP overa non standard port). This probably all sounds really techie but if you ask a techie Question you will normally get a techie answer.

one other thought, you mention another address that redirects to your aol one. whose that with? you could try setting your email client up to use that one as the sender(see comment about whether AOL will let you do tyhis though)