A review of SPF, DKIM and DMARC and how they help authenticate your domain’s outgoing email
Protocols
Understanding HTTPS and SSL Certificates
Explains HTTPS and SSL certificates, including how they work, why they matter, and how to obtain and manage them
IMAP vs POP3: A Quick Comparison
A quick comparison between IMAP and POP3
Setting Up POP3 Email
Guide to using POP3 instead of IMAP if it must be used