What is an email list?  It is a list of folks who share at least one common interest/theme.  They subscribe to the list.  Anyone on the list can ask or answer questions.  Though sharing many things with a bulletin board format, this is ran through your email.  When anyone sends email to the list, everyone gets a copy in their inbox.  Two places to start your email list search is on US Gen Web and http://egroups.yahoo.com.
https://gregathcompany.wordpress.com/tag/inbox/
gregathcompany.wordpress.com
crawl=CC-MAIN-2020-05
64230
application/http; msgtype=response
sha1:S5IYQTZZJBKO4EWKYOVRZ45BPNFLU6PM
<urn:uuid:d2831e1f-23cd-4dbd-a60c-00ad87f00081>
2020-01-19T10:24:54Z
192.0.78.12
application/xhtml+xml
sha1:2XVCWAEQ7WQ3KO6HR5MIGQT5QSW42IU2
<urn:uuid:b4abc22d-d382-434d-82da-2fbf909170b4>
https://gregathcompany.wordpress.com/tag/inbox/
response
<urn:uuid:4b3e9335-fee2-4238-a3f0-38e868e27877>
isPartOf: CC-MAIN-2020-05
publisher: Common Crawl
description: Wide crawl of the web for January 2020
operator: Common Crawl Admin (info@commoncrawl.org)
hostname: ip-10-67-67-154.ec2.internal
software: Apache Nutch 1.16 (modified, https://github.com/commoncrawl/nutch/)
robots: checked via crawler-commons 1.1-SNAPSHOT (https://github.com/crawler-commons/crawler-commons)
format: WARC File Format 1.1
conformsTo: http://iipc.github.io/warc-specifications/specifications/warc-format/warc-1.1/