SMTP password correct, but not accepted

[bipbop]

I changed my FM password. Downloading mail in Thunderbird works, but sending does not. Not sure why that is. I'm using the exact same password in SMTP, but it won't accept it. I have not changed any SMTP settings.

Does anyone know what's going on?

[Fenman]

Is it to do with needing an app password for Thunderbird?

[bipbop]

Originally Posted by Fenman

Is it to do with needing an app password for Thunderbird?

Hmm, I looked it up in the settings (Settings → Privacy & Security → Integrations), but it seems to be for actual apps on iPhone or Android? I'm using desktop Thunderbird.

[bipbop]

Scratch that, it suddenly started working again. Must be Thunderbird that caches the old pw or something.

Thanks for your input, though!

[n5bb]

As pointed out by Fenman, an App Password is required for each third party app or program to access Fastmail, including Thunderbird. In other words, your main account password (used for logging into your account with a browser) can not be used by Thunderbird. The issue must have been as you say some password caching issue with Thunderbird. If you log into your Fastmail account with a browser and look at the Settings > Privacy & Security > Integrations tab, you will see the App Passwords used for Thunderbird, Outlook, mobile phone and tablet email apps, and other devices.

Bill

[bipbop]

The only thing that's on the Integrations tab is

iPhone (Mail, Contacts & Calendars)

I don't own an iPhone, and never have, so I'm not sure what that is about. But there are no other apps mentioned there.

And it says "Apps that don’t support modern authentication need their own password".

So is that why Thunderbird works without being seen under Integrations? Because I am in fact using the master pw for sending and receiving in Thunderbird. I did nothing on the Integrations tab.

[n5bb]

Many years ago you used your master password for third party apps, but that changed over 5 years ago. I have no idea why your setup is working. See:

https://www.fastmail.com/blog/whats-...app-passwords/

https://www.fastmail.help/hc/en-us/a...s/360058752854

https://www.fastmail.help/hc/en-us/a...up-Thunderbird

[bipbop]

Interesting. It shouldn't work for me, yet it does. Strange.

[n5bb]

Originally Posted by bipbop

Interesting. It shouldn't work for me, yet it does. Strange.

Look on the App passwords page and examine the Last access date/time values. My guess is that what is labeled “iPhone” is actually your Thunderbird app password and will show recent access. I don’t believe that Thunderbird can be used with the latest access method (API tokens).

When Fastmail first set up app passwords, they gave accounts a grace period to switch from using the master password to an app password. But that was roughly 6 years ago, I believe. Have you been using Thunderbird with your Fastmail account for that long? If you had it set up in the past and only recently started using it again, there might be a short grace period before it fails and requires an app password. But this is very surprising behavior to me.

Bill

[bipbop]

It says about the iPhone "This app has not yet accessed your account.".

When I look at the Login Log "show logins from other applications" they show "Master password (POP3) ", which is Thunderbird, based on location and IP address.

What do you make of it? I'm curious what's going on.