Email problem – The SMTP server “smtp.me.com” rejected the password on 10.6.8 system

The SMTP server “smtp.me.com” rejected the password on my 10.6.8 system. I know I'm using an older operating system. This work email has always worked, until last night 6/15/17. I haven't changed anything. I know my password is valid as I can access my mail in icloud. I prefer using Mail to organize my emails, download files, and reply.

I actually had this happen a few months ago with our personal email. Now with that email, it only works if I first sign into icloud, then when I type the password in mail, it will get new messages and be online. The password always has to be re-entered. Now I rarely check/use that email, but I highly rely on my work email. (I tried doing this same thing with my work email account, and it is not working.)

Very frustrating. I only use these email accounts on this mac. I don't have other devices. I don't have a smart phone. What changed with Apple, that is not allowing my mail to work on my 10.6.8 operating system? I have lots of graphic software that work with this system, but that are not compatible with the newer system. I use this for work. Everything is working great, except my incoming and outgoing mail.

I appreciate everything. Thank you.