Hello JamaicaA, thank you for your prompt and sincere reply.

I don't mean to be unkind , but it is not just once I have contacted support and they didn't know what to do. I tried once by phone and once by chat.  My time is valuable also.  I  have repeatedly asked for them to escalate this issue if they can't solve it, but they refuse to do so.  One single post solving this problem would help a lot of people.  I have read a lot of posts, and the customers really just gave up as they realized they are not getting anywhere and can't spend any more time on the issue.  I don't think this is the kind of customer support that I think your company intends, but maybe the internal policies are not inline with the customer experience.

As far as contacting an IT professional, in addition to my degrees I have been doing heavy duty IT work for nearly 40 years.  I founded what was once the second largest ISP in the entire state.  I sure there are people that know more about email and encryption and servers and such than I do, but there aren't many.  I have used openssl to verify that the server responds correctly to all requests.   In fact when I first configured this, it gave a very unhelpful error about not connecting and I figured out that it did not like that the certificate name on the server did not match the server name it was told to connect to.  I actually wrote long detailed post post to someone else with the same problem, and for other people who had the same issue, but as often happens with this forum it was deleted when I hit "Post" and I didn't have time to rewrite it.  It actually deleted my post on this topic twice before it actually posted it, but now I know to save it in Notepad or such before hitting submit.  Again, not impressive.  I would think that it would relieve the burden on the support stuff to have accurate articles in this forum, but I have seen the advice you gave above repeated to many people having the same issue and never once has anyone replied :"Thank You, that solved my problem". 

Rather than having a multitude of incorrect replies for people to read would it not be more beneficial to have one correct one?   Isn't there some way to get this question to someone who really understands how email works and can provide an intelligent reply rather than referring to the same articles, which assume the user is at fault and did not corrrectly configure the settings?

Showing Linux server logs to  your support people is like showing showing a book to a dog.  They appreciate that is looks important,  maybe even smells interesting, but they have no idea what to do with it.  I have tried this, but it is obviously above the level of the people that answer the support and phone, and they refuse to connect me to someone who actually understands what they are looking at.   Instead they make inane suggestions that really have no logical basis and are sure to do nothing more than waste my time.

I really believe this is a bug in Quick books and was not tested thoroughly, as the same setup using gmail works like a charm.  I do NOT want invoices being sent to a customer from a Gmail address!   Its unprofessional in my opinion and we receive many scam invoices through Gmail.  I do not want to make that impression on my customers.