Add providers section

Added instructions on how to set up aerc for use with protonmail.
I created a separate directory for providers.

3 files changed, 42 insertions, 0 deletions

diff --git a/index.md b/index.md
index a8b5af38..07c4c54e 100644
--- a/index.md
+++ b/index.md
@@ -13,3 +13,5 @@ to common problems. If you want to contribute, please send your patches to
   other programs.
 - [configurations](configurations/index.md) – A selection of various useful
   configuration entries
+- [providers](providers/index.md) – How to configure aerc for various email
+  providers
diff --git a/providers/index.md b/providers/index.md
new file mode 100644
index 00000000..fc7e8cb0
--- /dev/null
+++ b/providers/index.md
@@ -0,0 +1,5 @@
+---
+title: "aerc-wiki: Providers"
+---
+
+- [ProtonMail](protonmail.md)
diff --git a/providers/protonmail.md b/providers/protonmail.md
new file mode 100644
index 00000000..cd32095a
--- /dev/null
+++ b/providers/protonmail.md
@@ -0,0 +1,35 @@
+---
+title: "aerc-wiki: Providers/ProtonMail"
+---
+
+# ProtonMail
+
+Using ProtonMail with aerc is not trivial, as you will likely
+experience issues with the `protonmail-bridge` certificate, stored
+in `$HOME/.config/protonmail/bridge/`. The workaround is to add this
+certificate to the root trust database. Please note that this is tested
+on Arch Linux, and might not be valid on other distros. Run this command:
+
+```bash
+sudo trust anchor --store ~/.config/protonmail/bridge/cert.pem
+```
+
+For outgoing mail to work, you might have to change the SMTP
+configuration in `protonmail-bridge` and set security to SSL instead of
+STARTTLS.
+
+Example account configuration, using the default ports of
+`protonmail-bridge`:
+
+```ini
+[Protonmail]
+source   = imap+insecure://youraccount%40protonmail.com:yourprotonmailbridgepassword@127.0.0.1:1143
+outgoing = smtps+plain://youraccount%40protonmail.com:yourprotonmailbridgepassword@127.0.0.1:1025
+default  = INBOX
+from     = Your Name <youraccount@protonmail.com>
+copy-to  = Sent
+```
+
+The first time you run aerc with this configuration you can expect a
+very long wait before anything shows up in your inbox. This will be
+considerably faster on subsequent launches.