Gmail has certain limits in place. For instance, the maximum size of file attachments that you can include in an email message is 25 MB while the total storage limit for a free Gmail account is 15 GB.
Similarly, Google also limits the number of email messages that you can send through your Gmail account in a day. If you exceed the daily quota, Google may temporarily disable your Gmail account without any warnings and you may have to wait for up to 24 hours before you can regain access to your Gmail mailbox.
Gmail Limits for Sending Email
Gmail isn’t designed for sending bulk email. If you are planning to send an email message to a large group of friends using Gmail, do read the following rules to avoid temporary lockdown of your Gmail:
Rule 1: You can send emails to a maximum of 500 recipients per day through the Gmail website. Try exceeding the limit and your Gmail account may get temporarily disabled with the error – “Gmail Lockdown in Section 4.”
It is important to note that this limit is around recipients and not messages. Thus you can send 10 emails to 50 people each or 1 email can be addressed to a maximum of 500 people.
Rule 2: If you access Gmail via POP or IMAP clients, like Microsoft Outlook or Apple Mail, you can send an email message to a maximum of 100 people at a time. If you exceed the limit, your account may be disabled for a day with the error – “550 5.4.5 Daily sending quota exceeded.”
Rule 3: Always double check email addresses of recipients before hitting the Send button in Gmail. That’s because your account may get disabled if the email message contains a large number of non-existent or broken addresses (<25 ?) that bounce back on failed delivery.
Rule 4: You can associate multiple email addresses with your Gmail account and send emails on behalf of any other address. However, when sending mail from a different address, the original account’s message limits are applied.
Also see: 10 Most Important Google Pages
Rule 5: If you are sending emails through Google Script, like in the case of Gmail Mail Merge, the daily sending limit is 100 recipients per day for free Gmail accounts. You can use the MailApp.GetRemainingDailyQuota method to know your existing quota else the script will throw an exception saying – “Service invoked too many times.”
If you wish to send more email messages through Google Scripts, you’ll have to upgrade to Google Apps. Even then, your sending limits will be only be increased after a few billing cycles or if you have opted for 5 or more users.
This is slightly unrelated but still important. Google, as per their program policies, may disable your Gmail account permanently if you don’t check your Gmail email for a period of nine months.