Greetings,
We understand your frustration. This is definitely not the experience we wanted you to have had & we're truly sorry for the discomfort caused.
We'd like to inform you that our developers team have already resolved the false detection issue with webmail services.
Please update the virus definitions of your AVG Internet Security as mentioned in this article, restart your computer once & check if the issue persists.
If the issue still persists after making sure that the Virus definitions and your AVG Antivirus program is up to date, please share us a screenshot of the threat message you've received, so that we can check & help you accordingly.
You can post the screenshot here in your topic. Click on Answer & then click on the Image [mountain symbol] & follow the instructions.
Note: Kindly click on "See Details" on the threat pop-up and then share us the screenshot.
Thank you for understanding in advance!