In 2012, BigCommerce launched an integration fund, which lead to hundreds of third-party apps for its platform. Recently BigCommerce launched an expanded partner program with new certification tiers —certified, premier, and elite — to strengthen and showcase app integrations.

Read more: 21 Apps for BigCommerce, to Extend and Enhance
Here's a quick explanation of all the fields:
Description: it's an informal name associated to your SMTP server.
Server name: the actual SMTP specification. Below you find a handy list of all the server names for the most common email providers.
Port: SMTP servers normally use port 25 to work, but there are other options.
Connection security: the standard SMTP email transfer goes without encryption, so it can be a good idea to secure it with STARTTLS or SSL/TLS.
Authentication method: it can be a plain text password, a cyphered one, POP before SMTP, CRAM-MD5, KERBEROS, NTLM, etc.
User Name: your email address.

Read more: SMTP server provider