Search Results: when to discuss marriage

I've already posted the letter on here for review, but I started dating this absolutely amazing girl in 2013. By spring 2014 we were exclusive with each other. We broke up at the end of summer because she was Mormon and I wasn't. Plus her parents didn't like me for that reason alone.
In November 2015 I reached out to her after a dream of her, and after telling me her frustrations about our break up, she said she didn't want me in her life. A few months later, she reached out to me and after a few weeks of talking again, she revealed she decided to go on a mission, and I confessed my love for her. She and I got into a relationship again and even discussed marriage but she said she would accept for real when she returned. She left in December 2016.
Because of her departure and the mission, she broke things off and kept trying to convert me. My Mormon friend said that she's just on a religious high, and things may change when she comes home.
She comes home in a month, and I wanted to send this letter to her to try to reconnect with her.
While we were dating, her parents liked to talk shit about me to her, and it took me confronting them and saying how I felt about her for them to ease up. But they never acknowledged me for that. Her mom told me before she left that I was very important to her daughter, and she gave me her cell phone number so we could get to know each other while she was on her mission.
But during her mission, the mom never replied once to the three total messages I sent. It's been over a year since we had any contact whatsoever. I have to send the letter to their house address. Is it likely they will make it so the letter is never seen?

I started dating this absolutely amazing girl in 2013. By spring 2014 we were exclusive with each other. We broke up at the end of summer because she was Mormon and I wasn't. Plus her parents didn't like me for that reason alone.
In November 2015 I reached out to her after a dream of her, and after telling me her frustrations about our break up, she said she didn't want me in her life. A few months later, she reached out to me and after a few weeks of talking again, she revealed she decided to go on a mission, and I confessed my love for her. She and I got into a relationship again and even discussed marriage but she said she would accept for real when she returned. She left in December 2016.
Because of her departure and the mission, she broke things off and kept trying to convert me. My Mormon friend said that she's just on a religious high, and things may change when she comes home.
She comes home in a month, and I wanted to send this letter to her to try to reconnect with her.
Please share what you think. I really need advice on it.

So, in December 2016 my long time girlfriend went on her mission for the LDS church. Although I'm not LDS , I dated her for 4 years and we discussed marriage before her departure. We got on Rocky ground during her mission and we have stopped talking.
I know she's just on an religious high, and I don't want to lose her, and she should be home sometime in June. I have a plan to send her a letter to try to remind her I still love her and I want to be with her. I dunno why I just have felt and know it's the right thing and what I should do.
My question is when should I send the letter?
My only concern is how it looks to her if she receives it right after or even shortly after she returns...
When should I send it? I don't expect her to reply, but when would be the most impactful if she returns in June?