Note: the use of newsletter.conf file is deprecated, use the platinum.conf instead.
Platinum Newsletter system lets to track the bounces and fully manage them. Since version 4.2 the bounce management and configuration has simplified and realies on VERP standard (see, for example, the Postfix description of VERP).
VERP works as follow: on every outgoing message a "return path" is added (it's an email address) so every mail server in the chain from the sender to the receiver knows where to send an error reporting messages when the email cannot be delivered.
The return path is composed in a special way: the user/account part of the address (firstname.lastname@example.org) is splitted in two distinct parts, separated by a VERP separator (usually the "+" sign). So the final return path address will be:
The "bounce" is an email account specifically made to collect delivery error messages, while the [something] part is used by mailing system (like the Platinum Newsletter module) to put in an identifier of original recipient.
When an error message is sent, for example, to email@example.com, looking inside the "firstname.lastname@example.org" mailbox a bounce analyzer finds the message and extract "33454" which identify a newsletter subscriber. This way, that subscriber can be marked as "bounced" and no more email will be sent to him.
How to configure Platinum
Every newsletter emal sent from Platinum can be marked to track bounces: that means the special return path seen above will be added on outgoing messages.
To configure the mailbox where delivery error should be sent, the file "platinum.conf" must be modify. Any configuration regarding the Newsletter system, is prefixed with "newsletter.".
Pay attention: the mailbox must support the VERP. Most of the modern mail servers support it, by the way.
Inside the platinum.conf under the key "newsletter.bounce.address" you must specify the account that will collect mail delivery error messages. Following the previous example, your bounce address might be "email@example.com". Platinum will change it when need adding its own "+subscriber_id" obtaining a firstname.lastname@example.org.
The you need to configure the access to the mailbox. You can choose between imap or pop3. The protocol is set with the configuration key "newsletter.bounce.mail.store.protocol" (see "platinum-sample.conf" for examples).
Once the protocol is set, another group of configuration keys let you to specify the credentials, host and port to connect. Using as example the imap protocol, those configuration may look like:
You can use GMail to collect delivery error messages, but it requires to connect via SSL. The last three keys ar for that. If you do not need the SSL connection, you should comment then out (add a # before each line).
Is it working?
The bounce analyzer runs as specified on scheduler.conf file, usually once a day. To see if there are error, look at the [dataDir]/logs/root file (it's a text file, open it with a common text editor) and search for VERP. If you find a "connect failed" probably the credential inside the platinum.conf are wrong.