If you are a Google Gmail user and are regularly sending emails in your network, you should keep this in mind that Google has set up a maximum email sending limit which is 500 emails.
You are not allowed to send in more than 500 emails or 100 emails if using a POP or IMAP client like Microsoft Outlook or Apple Mail. If you try to send more emails than the above limits your Gmail accounts will be deactivated for 24 hours and will get re-activated automatically.
If you are looking to send bulk emails why not use a email management software or program because in the normal way your account with google can get flagged and if disabled you can lose a lot of your important emails.
You also need to always add your important contact emails in your contact white list so they are given more preferance and are always delivered on time, rather than being moved to the spam/junk folder.Gmail users can mark and unmark any message as spam, at any time. To increase the inbox delivery rate of your messages, make sure that all recipients on your distribution lists actually want to receive the mail.
Normally there are two ways for Gmail to understand that the recieved email is to be delivered into your inbox which are :
1. The From address in the incoming email is added in your contact list and has been marked.
2. You mark any of the senders email as “Not Spam” guiding gmail to notify that the email is in your white list and should be delivered to your email.