How does request for new pics come? Mail or email?

[Snowisland]

I am visiting my husband in Canada until May. He received SA in mid December.
I see lots of people getting requests for the new size immigration photos.
I went ahead and got new photos made but am not sending until they are requested.
But since I am not in the US at my mailing address I am hoping a request for new photos will come via email, which I did provide.
If you got the request did it come by snail mail or by email?
Thanks.

 

[sdh]

by email for us.

 

[floomy]

VO requests additional docs through email while processing app.

only COPR was sent via mail.