Well, if there was a mandatory subscription fee, having a staffed customer service line might be appropriate, but Thunderbird is free, so support is voluntary. We do this all on our free time. Upgrades generally cause no problems, but it may depend on how old your version is. To be safe, you may want to make a backup of your profile, which is probably at c:\users\yourid\appdata\roaming\thunderbird\profiles. Unless you are using a version several years old, I don't anticipate any problems. Note there are several new features in latest version and I encourage spending a few minutes to look at differences. Good luck.