Jesse's Mistress to Sandra:

So Sorry

4/26/2010 10:30 AM PDT BY TMZ STAFF
TMZ has obtained a letter that Melissa Smith -- Jesse James mistress #2 -- faxed to Sandra Bullock's agent on Sunday, apologizing for her alleged affair with Jesse ... and it's pretty audacious.

Smith wrote to Sandra, "I felt I needed to reach out to you and tell you how deeply sorry I am for everything that you've been through."

Smith goes on ... "And I know nothing I can say in this letter is going to make the pain of my actions go away." 

And the mea culpa continues: "... I am sorry for any hurt or pain that I have caused you.  My actions of engaging with a married man are unforgivable.  I never meant you any harm."

Smith continues, "I compromised my beliefs on several occasions and as a result will never forgive myself."

Melissa closes the letter, "Please contact me if you wish to discuss on the phone or in person."

Don't wait by the phone, honey.