The license fee of eM client is actually neglectable, if you count the countless hours wasted of meetings that the program just does not send out!
I work with various clients and have to therefore different mail accounts, Microsoft Exchange, Google, Apple, … eM Client is supposed to do integrate all that, just as a matter of fact, it only appears so, I had at least 20 cases, where meetings that I sent out, never reached the other end. even checking if it was in the spam folder, as having now tested it, by always putting another dummy e-mail address in CC to check if it was sent out, it indeed fails in 3 out of 10 cases!!! How is that possible?? This leads to a huge inefficiency and even loss in opportunity costs for my business…
Therefore everyone out there who is considering to use eM Client as an alternative… DON’T!!!
In most cases the invitation is sent by your calendar provider not eM Client, unless you create the event in a Local Folder in which case eM Client will send the invitation. I suggest as a first step, you contact your calendar providers to find out why they are not sending the invitations.
But if you mean emails you are sending, if they are in your Sent folder, then they have been sent by your email server, because in most cases your email provider creates that sent message, not eM Client. That is certainly true for Exchange and Google accounts. If the messages have been sent by your email provider, but have not reached the recipient, your email provider should inform you they couldn’t deliver them. If the messages are not in your Sent folder, they have not been sent, and you will find them in the Local Folder Outbox. You will also find an error in Menu > Operations > Log tab to say why the message could not be sent.
I do suggest though, that as a Pro license user you open a support ticket with us. We can investigate some logs to see what is happening.