RaphaŽl Rousseau - 2011-03-25 02:02:27 - In reply to message 2 from Manuel Lemos
Well, I fear I've been misunderstood.
When one sends an e-mail, (s)he wants first the message to be actually delivered, and only secondarily that it arrives quickly.
So considering *only* the speed is not the major concern. Dealing only with PHP hides what is mainly necessary to have the message read... The sender would prefer it to arrive slowly in the inbox rather than finish quickly in the spam box of the e-mail service provider...
Respecting policies of e-mailing is not optional, it's a guaranty of long-term sustainability. See references in my previous comment.