Joe Manganiello didn't shoot Sofía Vergara a courtesy text before releasing his memoir "Bloodlines" ... because we're told he didn't feel he needed to let her know he was going to trash her in his book.

Sources familiar with the situation tell TMZ ... Joe didn't give Sofía an advance copy of the memoir -- or even tell her what stories he'd be telling from their time together.

In fact, our sources say he never even told Sofía he was writing the book because they don't talk ... he felt he had a right to tell his truth and she should've already had an idea of what he would dive into.

Besides, we're told Sofía's previous public comments about their relationship took Joe by surprise ... and he's just responding to those comments to try and clear his name -- something else that shouldn't come as a surprise to her.

As we reported ... Joe dropped a bombshell in "Bloodlines" -- claiming Sofía ridiculed him despite a serious autoimmune disorder he was fighting.

Sofía's son, Manolo, seemingly took a shot at Joe after he released the book ... posting about narcissistic men on social media, which Sofía reposted.

Joe sidestepped the allegations in an interview with CBS.

Remember ... Joe and Sofía were married for seven years before separating in July 2023 ... and he's the one who filed for divorce. The split was finalized six months after he filed.