Overview
SMTP Error 447 occurs when an email exceeds the recipient limit set by the mail server. This error can prevent emails from being sent successfully through your site, particularly when sending to a large number of recipients at once.
Causes
The main cause of the SMTP error 447 issue is exceeding recipient limits. Some email clients and servers often cap the number of recipients that can be included in the “To,” “CC,” and “BCC” fields of an email.
When you exceed this limit, the server is unable to process an email directed to too many recipients at once, resulting in this error.
Solution
To resolve SMTP Error 447, we recommend knowing your server’s limits. Familiarize yourself with your SMTP server’s recipient limits. Ensure your emails comply with these guidelines.
Alternatively, consider splitting the email recipients into two or more lists. If you need to communicate with more individuals than the limit allows, divide your recipient list into smaller groups.
Then, you can dispatch your message in multiple batches, adhering to the server’s limits for each send-out.
Note: Remember to count recipients in the “To,” “CC,” and “BCC” fields combined when considering the limit. For example, if your server permits only 30 recipients per email, ensure the total across all these fields doesn’t exceed 30.
That’s it! Now you know the common causes of SMTP error 447 and how to resolve it.
Would you like to improve your site’s email deliverability with an SMTP plugin like WP Mail SMTP? Consider configuring an additional connection to use as a backup mailer.