Gmail Blocked For "less secure" Apps
A friend, who I set up with Seamonkey and script blockers for surfing on his MBP, also uses SM's email client with his gmail account. A few days ago it stopped retrieving messages, but the account was still accessible via browser. While wrestling with the issue on his own, at some point Google pushed a form in front of him. He's not a techie, but recalls it contained verbiage about accessing his account from other locations. He didn't know the answers to some of the questions so closed the window midway and called me.
I suggested that he make sure that POP was still enabled, he did that, still no retrieval.
Today I accessed his account via browser. Last night they sent him an email stating that Gmail would no longer be accessible from less secure devices, and offered a link to a simple page where this feature can be turned off. After doing so, with the usual dire warnings to be acknowledged, I found a page which explained the policy in greater detail, which I will paste below. Note that no Google product, regardless of version, is on the list of less secure apps, but Apple and Microsoft (also T-bird) are found wanting.
"Allowing less secure apps to access your account
Google may block sign-in attempts from some apps or devices that do not use modern security standards. Since these apps and devices are easier to break into, blocking them helps keep your account safe.
Some examples of apps that do not support the latest security standards include:
The Mail app on your iPhone or iPad with iOS 6 or below
The Mail app on your Windows phone preceding the 8.1 release
Some Desktop mail clients like Microsoft Outlook and Mozilla Thunderbird
Change account access for less secure apps
To help keep Google Apps users' accounts secure, we may block less secure apps from accessing Google Apps accounts. As a Google Apps user, you will see a "Password incorrect" error when trying to sign in. If this is the case, you have two options:
Option 1: Upgrade to a more secure app that uses the most up to date security measures. All Google products, like Gmail, use the latest security measures.
Option 2: Change your settings to allow less secure apps to access your account. We don't recommend this option because it might make it easier for someone to break into your account. If you want to allow access anyway, follow these steps:
Go to the "Less secure apps" section in My Account.
Next to "Access for less secure apps," select Turn on. (Note to Google Apps users: This setting is hidden if your administrator has locked less secure app account access.)
If you still can't sign in to your account, the "password incorrect" error might be caused by a different reason."