Webmail
https://webmail.webfaction.com/
Webfaction Account
Webfaction MX server setup
https://docs.webfaction.com/user-guide/domains.html#mx
Webfaction Configure Email Client
https://docs.webfaction.com/user-guide/email_clients/other.html
Host on DigitalOcean, Emails on WebFaction
Assumes you have a droplet and hosting is setup for the domain.
On the DigitalOcean DNS management page, click the MX tab.
hostname: @
Mail Providers Mail Server: mx7.webfaction.com
Priority: 10
TTL: 5 or greater
Then click [Create Record]
Do the same for mx8.webfaction.com and mx9.webfaction.com (docs above)
On Webfaction create a mailbox
Create one or more email addresses for that mailbox using the same domain as hosted on digitalocean.
Setup your email client (thunderbird) to manage the emails (see link above for docs).