Free Email Forwarding Services

Forward your email from one email account to another.

addy.io

DOMAINS: @anonaddy.com and @anonaddy.me (paid users have access to additional choices)
The addy.io service offers two types of email forwarding: using their domain names, or your own. If you choose to use a domain name you own, you will need to change its MX settings so that addy.io takes over responsibility for email routing for the domain. The underlying software behind the service is open sourced, meaning the code is available for anyone to check.

American Radio Relay League

DOMAINS: @arrl.net
Free email for members of the American Radio Relay League (in a sense, it's not free, since you have to pay to be a member of the ARRL - but you might not know about this particular benefit of membership.)

CloudNS

DOMAINS: Whatever domain name you like
CloudNS offers email forwarding for people with their own domain name. By modifying your domain name's DNS settings to use CloudNS's nameservers, you can forward emails addressed to your domain name to any other email address you own. This lets you have a professional-looking email account even if you don't have a website associated with the domain name you own. Behind the scenes, the emails are going elsewhere, e.g. to your Gmail or other public email address.

DuckDuckGo Email Protection

DOMAINS: @duck.com
Email forwarding service with in-built privacy protection: forwarded emails have any email trackers embedded in them automatically stripped out before the emails are forwarded to you. In addition, you can generate private email addresses that you can give out to just one person or company to control who emails you.

Firefox Relay

DOMAINS: @mozmail.com
Firefox Relay provides free users with up to 5 "masked" email addresses that they can use to forward emails to their true email address. The service supports attachments of up to 10MB. Paid users have access to additional features, and the ability to make unlimited masked emails and to create email addresses of the form subdomain.mozmail.com.

Google Gmail

DOMAINS: @gmail.com.
Google offers a free email forwarding option as part of its comprehensive Gmail service. You can choose to either forward all incoming emails to a different email account, or forward messages selectively based on filtering criteria that you specify. Only the emails that match your filters will be forwarded. You also have the option of storing a copy of forwarded emails in your Gmail inbox.

SimpleLogin

SimpleLogin allows users to create up to 10 free email aliases that can be used to forward messages to a different email account. The service has no bandwidth limits. A premium tier included PGP encryption, unlimited email aliases, and the ability to use the service with your own domain name.