I believe you may be using the Daily version, never recommended for regular use, as it's likely to crash and burn. Please click help>about if unsure. If your intended use is for day-to-day email, I suggest you go to https://www.thunderbird.net/en-US/thunderbird/all/ and dowload either the ESR (140) or the monthly (150) releases, as they are both stable

I'm using Thunderbird 152.0a1 (2026-04-22) on Windows 10 64 bit. When I click the "Get Messages" button or File > Get New Messages for > [my e-mail account] nothing happens. The only way I've found to check for messages manually is by closing and re-opening the program.

I'm not aware of any problems in this area. State your mail provider, and whether this happens with Windows started in Safe Mode.

It's fine to be running apha Thunderbird for testing and we welcome the effort. And if you continue running it, there is a group we can refer you to where users help each other.

Gmail. Booted into normal, not SAFE mode.

Thanks.

Please test whether this happens with Windows started in Safe Mode, with networking enabled - https://support.microsoft.com/en-us/help/12376/windows-10-start-your-pc-in-safe-mode