We are regularly having a problem generated by the CBSubs AcyMailing plugin.

The error is:
1062 Duplicate entry 'xxx@xxx.com' for key 'email_UNIQUE'

It seems that, if someone has previously subscribed to our mailing list as a non-registered guest through AcyMailing and then they try to register as a member, there is a point in the registration process where that error is generated. For example, after registration and confirming their email address, when they are taken to the payment page. If they choose Offline Payment and then on the basket page they click the CONFIRM_OFFLINE_PAYMENT link, they end up with that error.

It also happens in admin backend when we are trying to edit the profile of a particular user. We occasionally get this error and when we look into it, it seems that the issue is that the member's email address is already in the AcyMailing list but not associated with their current user id.

Is there some setting or some place we should look to avoid this? For example, is there a way (perhaps an Auto Action) that we can associate an existing email address in AcyMailing users to a newly created user account that wants to use the same email address as they used when they subscribed to the mailing list before they were a member?

Also we notice that when a member changes their email address in their profile (we use CB Reconfirm Email), the email address for them in AcyMailing does not change to the updated email address.

Under the AcyMailing tab in Integrations for each plan, we have it set so that new members are automatically registered to our mailing list and Remove on plan deactivation is set to No.

CBSubs is version 4.5.2+build.2021.06.25.17.09.42.53205149f
Community Builder is version 2.6.0+build.2021.06.28.15.38.58.c5219011c
AcyMailing plugin is version 4.5.2+build.2021.06.25.17.09.42.53205149f
AcyMailing Starter extension version 6.16.4

Sounds like something else installed is adding them to AcyMailing, but isn't adding their user id. CBSubs AcyMailing will always add their user id via AcyMailing API, but since AcyMailing has a unique database key on the email column it errors. Are you using any other means of subscribing to newsletters than CBSubs AcyMailing? If so I recommend reviewing those other usages.

As I said, people are able to subscribe to our mailing list without a registered membership. After they have subscribed as a non-member guest to the mailing list, they decide to join as a member. As part of CBSubs plan AcyMailing integration, they are automatically subscribed to our mailing list. There is nothing else in our system related to AcyMailing except the Community Builder AcyMailing plugin.

All we need is for that plugin to recognize that when a person is registering as a Community Builder member that if the email address they are using is already existing in the AcyMailing database because they previously registered as a NON-MEMBER, in which case the Community Builder AcyMailing plugin connects that existing email address to the newly created membership account.