Well, there is a solution. Google allows you to make 'App Passwords' which is logins for your Gmail that does not need two-factor authentication. Instead you get a fairly complex password that you can then enter into your App still be allowed to send mails.
Btw: This also works for Google Apps accounts!
Here is how to do it.
- Goto Google Account settings.
- Scroll down to 'App passwords' and click it
- Enter your Gmail password
Since you are adding/changing some security settings, Google will ask you to provide your password.
- Click on 'Select app' and choose 'Other (Custon name)'
- In the field enter 'Lightroom' or something that will remind you what you are using this account for, and click Generate
- You will be presented with a app password consisting of 4 4- character blocks. Select and copy this password and click Done
- Open Lightroom
- Click CTRL+Shift+M (or File -> Email photo...)
- In the Service Provider field, select Gmail
Fill out your Account name (usually your real or company name)
Add your email address
Finally paste the password from step 6 into the Password field
- Click OK and you are ready to go!
Click in the Validate button and Lightroom will check if the settings are ok. If they are, you will see a green dot next to your Account name and right underneath it, it will say Validated.
There you go. You can now send mails from Lightroom even though you have two-factor authentication setup for your Gmail account.