Gmail smtp Sending Limits Gmail smtp Sending Limits lets google to keep its Inbox clean from spammers. Some of the sending Limts of Gmail SMTP’s are: Maximum of 500 recipients per day through the Gmail website. POP or IMAP clients( Microsoft Outlook or Apple Mail) can send a maximum of 100 at a time. Over Google Script, the daily sending limit is 100 recipients per day for free Gmail accounts. With SMTP sending Limits on gmail google keep a tidy email system with proper labeling and SPAM mechanism , While using transactional emails the limits are decent and the limits blocks only when SMTP accounts used for Newsletter and bulk email sending , if you are using Gmail for Bulk email try using Mandrill App or Mailjet instead.