Hi {First Name},
I have tried emailing you a couple of times over the last few months and have not received a reply thus far. I am going to assume you are not interested, and this is totally okay. No hard feelings. The timing is wrong I guess.
You can always get in touch with me if you ever require {name of service offered}. Although I won't be reaching out again, you are welcome to keep my contact information.
[Add your information]
Wishing you all the best!
Best,
{Your Name}