If not, use your refresh token to generate a new access token.Check whether you have a valid (unexpired) access token.

So then, you do all this setup, and your connection procedure looks like this: This is the one you need in order to actually connect to GMail to send mail. This is generally long-lived, expiring after six months of disuse or after too many other refresh tokens have been generated. That will generate another string of text which you can convert into tokens. Somebody with access to that account will need to visit a Web page and grant access to that application for the GMail account in question. Next, your application requests access to a specific GMail account (the one you plan to send mail from). Then you get an application ID and “secret” (a string of text), with which you can generate tokens. Instead of usernames and passwords, OAuth deals with tokens.įirst, you set up an application.

Configure your JavaMail sender to use OAuth for authentication.Configure the Google account to accept connections from less secured applications less secure app switch.If you use JavaMail and/or SimpleJavaMail or the Spring MailSender to send email through a Google mail account, you get an authentication error saying Google mail blocks less secure apps.Īt that point, two things are left for you to do: The original articles are here Chariot Solutions: Sending Mail via GMail with JavaMail and here JavaMail OAuth2 Support but in order to get my application to work I had to make some changes that included parts from both articles.

K9mail oauth2