Resolved Question: I get paranoid whenever I hear my BF cell beeps for text messages. what should I do?

Last week I saw an email from my BF that he sent to a female married friend that says I have been thinking about you so I checked your flight status because I miss you already (attached flight status) my BF claimed he did not send that message and it could be a spam mail etc. I asked him if he has a crush on his friend or if there is something going on. He said no and he won’t cheat on me. The girl is married with 3 kids. He recently introduced her to me but they’ve been friends for years now. He also said that he won’t do such a thing and he would not introduced her to me if there is something going on. Since then everytime someone email or text him, I feel that it was that girl He also told me that he doesn’t have a crush on her. SHe is about 7 years older than us. He said he will not be able to look it to my eyes if he is cheating. I already confronted him about this and I still feel that he was the one who sent it. Although I’ve known him for 14 years and he always show love and care and I know he doesn’t lie. I also talked to his female married friend and she seems nice. It just that the wording on the email is like not appropriate for female friend. Although my BF is very sweet, he is just probably concern with that friend’s flight status and she was arriving from overseas that day. Should I stop worrying? I guess I’m just paranoid. Please advice I want to stop thinking about it. What should I do? I want to trust him again. thanks