Tom
With Mandrill (SMTP), a major limitation is for Meta-Data - which is how/where you're gonna embed the "ID" that you want to come back.
They have a significant size restriction using SMTP - but REST is fine.
The deciding factor is:
Mass send 1 Email to a bunch of people (same email, 1 send to Mandrill with a list of recipients) vs
Send a unique email to a bunch of people (many sends to the host)
The Mass transaction has to have a long string (in the JSON) binding the Email_ID# to each recipient.
This string exceeds the small 200char buffer they allow for this in SMTP (buried somewhere in the SMTP docs).
Just pointing this out because someone could decide to go an SMTP route (which uses URL embedded parameters) and then find a business case where they hit this limitation and have to start all over via REST anyway.
Hey, I thought this is a Payment Processing thread? :roll:
