How do you correct mail destination

[peled]

It is either a bug or I miss something here.
You may try it out, maybe you'll find a way to solve the mystery...

1. I open my E-Mail that was defined for G-Mail (not exchange).
2. Wrote a letter with some mistake in the destination address and push the send
3. the letter was not sent, and it was moved automatically into the OUTBOX.
4. So now I want to correct the address.
5. I click on the letter
6. It opens it properly.

Now for the life of me I couldn't find a simple strait forward way to update or
change the address.