Hi Yuko!
Current PB releases have built-in support for MAPI. PB 2022 Release 1 coming out later this year will support built-in SMTP.
There are various Web API alternatives that can be used as both PB versions support Web API calls via the HTTPClient object class. There are also some 3rd party alternatives as well that work with PB Apps as well. Google is your friend here. ;-)
Regards .... Chris