I have trouble interpreting the email sending limits of Google Apps (for business account).
Messages per day: 2000
Clear, I send 2000 emails per day.
Recipients per message: 2000 (500 external)
Not so clear. I can send an email to 2000 recipients. So basically I could send 2000 emails to 2000×2000 recipients per day. Does external users mean our customers and partners?
Total recipients per day: 10,000
Whoa, so I can send emails to only 10,000 recipients, not to 2000×2000. So I can send at most 2000 emails a day, but to no more than 10,000 recipients. I understand that "Individual addresses count in every mail sent; 5 emails sent to 10 addresses count as 50 recipients". Are the total recipients internal or external recipients?
External recipients per day: 3,000
This clears it more. So I can send emails to 7,000 of my colleagues (???) per day and to 3,000 of my customers, partners etc. This is including individual addresses.
Unique recipients per day: 3000 (2000 external)
So e.g. I can send an email to 1000 customers and then send a follow-up email to 1000 of them (~2000 external recipients per day)
Recipients per message (sent via SMTP by POP or IMAP users): 99
I have no idea what this is. I am sending emails via PHP, not through GMAIL. Does the limit types above refer to emails sent from within GMAIL? Does that mean that if I have 100 registrants a day, only 99 of them will receive the welcome message because I send the emails by a script???
Best Answer
The last one is a limit set on messages sent using a mail client, rather than the Gmail web interface. If you are using PHP you are not using the web interface, correct? So no more than 99 recipients per message is your limit. All of these rules are to make it difficult to use Gmail to spam people. Best bet is to assume the most restrictive options are the default - the first limit you run into is the one that applies. So for example, if you send 2000 messages to 2000 different unique external addresses, one message per address, you have hit your external and daily limits, no more email until tomorrow. Four messages to 500 unique external addresses each (total of 2000 external addresses) would also hit the 2000 external limit but you would still be able to sent up to 1996 emails to internal addresses, provided you don't go over the total allowed limits for anything else.