I know this is old, but I need to do something similar. My thought is to send a message to function, which puts message in storage queue and returns 200 to client, then queue trigger runs on durable function, which conducts the data and communication stuff (mail, text), then completes by updating the queue message and sending response email if needed.

So Blazor App > Message > HTTP trigger Function > Queue > Queue Durable Function > Step #1 > Step #2 > Step #3 etc.

Can this work for both OP and for my needs? Thanks in advance.