使用GMAIL SMTP加快电子邮件的技术

I do have a system where there is an email notification function(USING GMAIL SMTP), my problem is when there is a multiple recipient it emails very slow. Is there a technique where i can fasten the emailing function? Can you please share it with me? My current set up is, i'll loop first the recipient; inside the loop i call a function that sends email. Other idea is to put the recipient in array then call the function; inside the email function i will loop the recipient. is there any approach to this?

Not easy to see why your program is slow unless you show your code. Remember though that GMail is likely to throttle your mail sending script if it thinks that you send to many mails to quickly.