multiple ip addresses for submission -- My Google Fu is lacking

[Max-Julian Pogner]

Hi there,

when a user clicks "send", the email client has to make some 
tcp-connection to some ip address.
what if the hostname configured at the email client resolves to multiple 
ip addresses?

i actually know the theory (either round-robin, or just the first, or 
try first and if fail then try next, possibilities to react if server is 
running but only makes garbage responses, etc..), but what behaviour do 
the "big" email clients actually perform?

i couldn't find the slightest answer using my google fu, nor does any 
email client of interest to me (ms outlook, thunderbird, k-9, whatever 
iphone is doing) seem to publish any kind of documentation in that regard.

could someone suggest me a page to read next or google search word to 
try out?


best regards,

Max