In case anyone else needs it, here's how to get a contact form working on namecheap shared hosting. I couldn't get mine to send using just SMTP from the Email plugin, or using Sendmail, but...
Set up an email address in namecheap cpanel -> emails
Contact namecheap support and ask them to open the SMTP ports, which are closed by default.
Install the Php mailer plugin from zip* via Admin -> Tools -> Direct install
Activate it and set:
Email from: [the email address you created]
Use these settings for the Email plugin:
Email Defaults
From address: [the email address you created]
SMTP Configuration
SMTP Server: cpanel server address - e.g server123.web-hosting.com
SMTP Port: 465
SMTP encryption: SSL
SMTP login name: [the email address you created]
SMTP password: [the password you used when you setup that mailbox]
Contact form
process:
- phpemail:
# To visitor
to: "{{ form.value.email }}"
subject: "Thank you for getting in touch"
body: "{% include 'forms/visitor.html.twig' %}"
- phpemail:
# To myself
to: "{{ config.plugins.email.to }}"
subject: "A message from your website from {{ form.value.name|e }}"
body: "{% include 'forms/data.html.twig' %}"
Thanks to mickidum for this handy plugin.
* Is there a reason that it can't be found by searching plugins or installed via command line?