I'm pulling my hair out here.......my site has over 5000 members so its crucial i fix this, please help.

My problem is very odd, I'm no php god so I'll try my best to explain. Currently I'm using nuke 7.5 and the site wont send mail to certain emails...example i can use hotmail and register and the site will send mail within seconds, but i use charter and it gets sent to "resend_mail" mod that we use. Gmail seems to work sometimes, only way I can explain this is that I dont think it sends mail to ISP mails. I had to make a huge actavate here link so that people wouldnt keep getting sent to a waiting list. My biggest problem is that I can send mass emailer or if a user needs their password they cant get it.

I can send and recieve mail just fine using the same email address through outlook or hoard. If anyone can help please let me know.

replace your \n"; with \r\n"; in the headers