A few of the interests I have and projects I follow use Google Groups to keep in touch. Essentially, these are just mailing lists that Google maintains. At any rate, while it's possible to subscribe to a group without having a Google account by sending an email to (group name)+firstname.lastname@example.org, if you do have a Google account and use GMail with aliases, it can be tricky to ensure that you subscribe using your preferred address. This is because Google, in its infinite wisdom, will subscribe your GMail address if it detects you attempting to subscribe under any alias that's associated with your GMail account. That has the side-effect that you won't be able to post to the group with anything but your GMail address.
Luckily there's an alternative subscription mechanism (which I spotted here). If you instead use the Google Groups web interface, Google won't have the opportunity to inspect your email headers and determine if you're using a GMail alias. So, you will end up with your preferred address subscribed to the group, instead of your GMail address.
The URL you need is https://groups.google.com/forum/#!forum/(group name)/join where (group name) is the name of the group in lower-case and with spaces replaced by hyphens. You'll be asked the email address you wish to subscribe. After filling it in, at that address you will receive the link to confirm your subscription.
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