Both the errors are pretty much clear and neat in their sense,
Quote:
Conversion from string "" to type 'Integer' is not valid
How can you convert an empty string to an integer? It should at least be a "0", or something similar. There is a safe way to parse the string to integers,
int number;
if(int.TryParse(your_value, out number) {
} else {
}
As already mentioned, the problem is that the server cannot take more connections as already enough clients have been connected. There are two ways to solve this:
1. Reattempt to connect, which would again (more likely) result in the same problem.
2. Tell the user that the server is not responding. Which won't be a good approach for UX.
Somehow, since you say that this was working then you need to wait or retry again later, their server might be expecting a load of users.
Also, you should check up against their subscriptions information to know why are they showing this error, an email service should not be down, if you are paying them for the service. If in the case of a trial, then it should be fine and you should understand this. :-)