Sometimes, while sending emails using your email provider's SMTP server, you might receive an error message as in the image below.
Your SMTP email provider would have rejected your mail for a few reasons.
Why did your email get rejected?
You may have reached your email provider's sending limit for the day. Please refer here for more information on Email providers limit
Your mailbox is temporarily not reachable.
Your email account is disconnected from the web application.
The text or links in your email message is suspicious.
A large number of recipients were added to Cc or Bcc.
What can be done to fix this?
Retry sending your email after 24 hours post rejection. To Know your daily sending limits click here.
When your mailbox is not reachable, the system tries to connect your email provider every 5 minutes. You can retry sending emails after 10 minutes.
Your mailbox can be disconnected due to invalid credentials, you must have updated your account's password, reconnect your email account with the product.
Remove every link asking for personal details.
While sending bulk mails, choose ‘Use Freshsales SMTP server to send emails’ under "Connect your email" option.