Coverage-Related Problems with Stock Email Client

[CoMoNexus]

Sometimes I compose a message and hit send, but it goes nowhere because the signal isn't strong enough for the client to connect to the server. When that happens, it goes to the outbox, but then it automatically isn't sent on the next sync, even when syncing manually. If I click on the message, I don't see a send button to force it out. Am I doing something wrong, or is the stock email client flawed in that regard?