Note: this is an experimental extension. We always recommend to use a professional delivery service to send your marketing email and get the bounces correctly managed. We cannot grant the extension will be able to detect all kind of bounces.
When a message is sent to an invalid or unreachable address, most of the time you’ll receive back a delivery error message as a response. If correctly formatted, those error notification messages contain a set of data, called DSN (delivery status notification) with information about the kind of error (temporary, permanent, and so on).
The Bounce extension tries to analyze those messages and find out if it has been generated by an email address in your database. If so, it will be marked as “bounced” and never contacted again.
Note of warning: Use a dedicated mailbox!
You need to set up a new and dedicated mailbox to collect delivery error messages and let this extension manage them. Messages will be deleted from that mailbox once processed. Do not use your mailbox!
If you use Post SMTP as SMTP plugin
If you’re using the plugin Post SMTP, be aware that the “return path” set on Newsletter Settings is not respected. If they can add an option to set that value (we should call it “Sender” but is a bit misleading for nontech humans), the return address needs to be set in that plugin.
How to configure this extension
The extension needs a dedicated mailbox (email address) where all the error messages are collected. The mailbox has to be accessible using the POP3 protocol.
To instruct externals to send error messages in the right mailbox, you need to configure the “return path” on Newsletter main settings with the email address you created in the previous step.
Hourly, Bounce opens the mailbox, reads all the messages, analyses them, and tries to detect if there are permanent errors reported. Extract the email address and mark it as bounced.
The POP3 configuration consists of a user name, password, hostname, and port (optional). Those parameters can be found in your provider’s instruction on how to configure a generic mail client.
If the mailbox can be accessed in secure mode (TLS, SSL), you can even select the security protocol to use but remember to set even the port (usually it differs from the standard 110 port number).
When it runs
The extension checks the mailbox every hour and processes up to 1000 messages (but this could change). For your convenience the last time the extension checked the mailbox and the next run are reported in the configuration panel.
Please note: if your blog has some resource-intensive background processes (for example you’re sending a newsletter to a big list) the bounce checks could be delayed or sometimes skipped.
If you use Gmail as a mailbox for your error delivery messages, the POP3 must be explicitly enabled since it’s not active by default. You can read more here.
Test the configuration and errors
Once you configured, you can test if the extension can connect to the POP3 server.
If the connection was fine, you have a success message with some debug info on top of the page.
The test extract 10 messages, analyze them but is a “dry run”, the extracted emails are not processed neither the messages are deleted. To check if messages are correctly retrieved try to send an email to your bounce dedicated mailbox.
If you got an error message
If you get connection timeout errors or generally an error message without more specific information, there are few options:
- the parameters you are using are not correct (for example the hostname, the password, the port, or protocol): double-check them with your provider; the most common errors is to use the incorrect host or the username which not always match the email address
- your provider has a firewall rule blocking the connection, ask them via their support tickets or try with different combinations of protocols and ports
- If you can read in the error text “getaddrinfo failed” it means your server is not able to resolve the host you provided. Double-check it and if correct ask the provider to check the server to grant it can resolve the pop3 host.
Bounce checking timing
The extension reports the last time it checked for bounces and the next scheduled check. If you not it is not running with the correct timing, you have a problem with your WordPress scheduler. Check on top of the page for an error message and take the time to read this page about the WordPress scheduler.
Why is important to manage bounces
Trying to send messages to an invalid address, again and again, is considered spammy behaviour and could be a reason to list your domain or your server on a blacklist. Detecting bounces lets you quickly react to invalid addresses and stop sending them more messages.