PPemail offers the common methods to sync your device(s) including IMAP, POP3, SMTP, and SSL/TLS.
IMAP & POP3 are for incoming (getting your email) while SMTP works on the outgoing (sending emails). SSL/TLS adds a layer of security but may not function properly on older systems. The best protocol for you depends on how you use email.
IMAP: Better when syncing across multiple devices
POP3: Best for keeping account information independent
See a detailed comparison between IMAP & POP3 at Wikipedia
SMTP: Protocol to send outgoing email
SSL/TLS: Required security feature
For most, the main decision is between POP3 and IMAP.
Because security is important, send all emails only through authorised SMTP and enact SSL/TLS. Update the device’s system if the current one prevents it.
We created PPemail for professionals who need portable yet secure email and file storage. Because clients pay for our services, by contract, we do not and will not commodify their activity. (MORE)