PHP/ GMail SMTP limits from site form results

Question

I am sending form results via smtp/php mail using gmail's servers. Is there a daily limit on how many results can be sent? Again, I'm not sending bulk email or anything, however, there's a chance thousands of people will use this form over the course of a week and I need a sure fire way to get these results to the users' emails.

I've tested a number of methods and only ran into problems with getting emails through to Gmail accounts- they wouldn't even appear in the spam folder (and sometimes they did). Using smtp.gmail.com worked without a hitch.

So is there a limit for sending results from forms via Gmail and if so, is there a way to purchase more? All I'm seeing are results for sending mass messages to multiple recipients, which is not the case in this situation. It's only needed for about a week.

Answer 1

Gmail does have hard sending limits. For Google Apps accounts it's 2000/day with smaller burst limits as well (http://support.google.com/a/bin/answer.py?hl=en&answer=166852).

They do not publish the regular Gmail limits, but anecdotally it's around 100/day from external clients (such as your app), 500/day from within the Gmail web client.

For sending to individual recipients you're probably looking for a transactional email service - see here for more discussion: Looking for bulk and transactional email-sending service

Disclaimer: I work for PostageApp, mentioned in the attached SO discussion

Answer 2

check here for a start:

http://www.emailaddressmanager.com/tips/send-email-limit.html

i found that the only reliable way to get through this is by testing:

• let your webpage send a number of messages in an hour

• check the result of those emails (PHPMailer i suppose?)

you'll find the current limit the gmail is now using (its not fixed and they surely doesnt tell you when it changes)

Answer 3

It's possible that your own ISP is holding back the emails, so delivering straight to GMail servers seems like a viable option (if all your recipients are on GMail that is). Not sure about any limits being imposed by them, but it's still a bit hard to figure out whether a message hits the spam filters.

An alternative could be Amazon SES (paid service, but their prices are relatively cheap). They provide a bounce/complaint loop so that you can check which recipients flagged your messages :)