A source revealed that John Mayer has penned a song for Jennifer Aniston, and this time he is ready to let her go.

John Mayer is letting go of ex-girlfriend Jennifer Aniston in a song. Although it has been three years since the two broke up, it seems like the 34-year-old singer has had a hard time letting go of his ex-girlfriend.

Some of his exes include Jessica Simpson and Jennifer Love Hewitt but has only written a song dedicated for the 43-year-old actress. The source says that his single "Shadow Days" was Mayer's farewell letter for Jen. And it seems like all of his exes have managed well on their personal lives except for him.

"Shadow Days is about Jen," a source reveals on Us Weekly. "It really took him a long time to get over her. He really loved her a lot."

"He wrote the song as a farewell letter knowing [Jen] would hear it. Ultimately he's done a lot of self reflection though and it he realizes they weren't right for each other," the source added

Mayer and Aniston met on April 2008. Along the way they have had multiple breakups and finally called it quits on late 2009. Jennifer is currently in a relationship with Justin Theroux for over a year now and Mayer has long been single.

After a string of popular girlfriends which all didn't work out, the source says that the singer is done dating celebrities and is looking for a "nice and non-famous" girl he would be able to relate to.

After his split with Aniston, he hasn't been in any serious relationship over the years. While he was rumored to have dated Taylor Swift back in 2010, it wasn't confirmed to be true.

Also Read:

Adam Levine Calls Jennifer Love Hewitt 'Aggressive'

Rihanna to Star in 'The Fast and The Furious 6'

RELATED STORIES