Alias completion question

[Jason]

I regularly use Tab to autocomplete alias names. Is there any way to 
differentiate between a name that is partially completed (due to there 
being several aliases starting with that string) and one that is 
complete?

For example, say I have an alias named johndoe and another one named 
johnnybrown. If I type 'jo' then hit Tab it will fill in 'john' and I 
have no way of knowing whether this matched and will be replaced by the 
email address when I hit Enter, or if it is only partial and will result 
in a bounced message because of an invalid address.

To prevent this, I usually press Tab one extra time to see how many 
matches pop up; just wondering if that's what everyone else does too or 
if there's something that would negate the need for the extra Tab press.

Thanks,
-- 
Jason