is the stream modified during logic A; I mean, why not to apply logicA & logicB at the same time? where is the restriction for that? 

depending on your rule to open the file... if you create a new one each time, will not work as expected, you may change to chek if file exists and create only if not and later open it and append new lines at the end...

did you try the DELETE %NOTRIGGER ?

did you configure a new email adapter? besides the SSL you will need to ensure the adapter is using SSL and TLS (no only SSL) and even you may try to set it to use the STARTTLS (Set smtp.UseSTARTTLS = 1 where smtp is: Set smtp=##class(%Net.SMTP).%New())

https://kinsta.com/blog/gmail-smtp-server/