We are seeing messages that ISendEmail is now obsolete in our code after upgrading to 12.1.3. I don't see any update/notice about this code being obsolete. What are we supposed to use now? This worked fine in 12.0.6.

We are seeing messages that ISendEmail is now obsolete in our code after upgrading to 12.1.3. I don't see any update/notice about this code being obsolete. What are we supposed to use now? This worked fine in 12.0.6.

I should also point out obsolete does not mean non-functional. It simply means its been replaced with a newer version, the older version remains and is functional and remains that way for at least 2 versions by our current deprecation cycle. It means no new development should use it and older usages should be updated as soon as feasible.
I believe ISendEmail.Send is non-functional in v12.1.3. We are not receiving any emails from this API and are seeing exceptions thrown while still reciiving OOTB emails from Verint.

We are seeing the following exception when trying to send an email to a valid user in v12.1.3 with ISendEmail.Send (Note, the user in this case received Verint's OOTB new thread email seconds before this):
User is not configured to receive email or is unable to receive email. (An error occurred when attempting to send an email.)