feat(wpcarro/blog): Publish "2FA and Gmail's \"Send mail as\""

Small blog post about how I configured myself out of my personal email.

Change-Id: Ibb8834b2150f94dba5f46a8ea634e7e9813b76a5
Reviewed-on: https://cl.tvl.fyi/c/depot/+/4817
Tested-by: BuildkiteCI
Reviewed-by: wpcarro <wpcarro@gmail.com>

users/wpcarro/website/blog/posts.nix

@@ -15,4 +15,11 @@
     content = ./posts/quassel-google-vm.md;
     draft = true;
   }
+  {
+    key = "send-mail-as-2fa";
+    title = "2FA and Gmail's \"Send mail as\"";
+    date = 1641497483;
+    content = ./posts/send-mail-as-2fa.md;
+    draft = false;
+  }
 ]

users/wpcarro/website/blog/posts/send-mail-as-2fa.md

@@ -0,0 +1,43 @@
+## Prelude
+
+This is a short story about how I configured myself out of my own email. Posting
+this as an exercise in humility, a tutorial for my future self in case of
+amnesia, and penance for my sins.
+
+## Background
+
+-   I have 2x Gmail accounts: **work** and **personal**.
+-   I configure **work** to send emails as **personal**.
+-   I configure **personal** to forward incoming emails to **work**.
+
+This allows me to use **work** and manage both of my inboxes as one. I recently
+added two-factor authentication (2FA) to **personal**, forgot about it, and
+spent a few days unable to send **personal** emails from any **work** device.
+
+## Symptoms
+
+Whenever I tried to send emails on behalf of **personal**, I'd receive the
+following error message as a reply:
+
+> You're sending this from a different address using the 'Send mail as' feature.
+> The settings for your 'Send mail as' account are misconfigured or out of date.
+> Check those settings and try resending.
+
+Useful error message if you ask me (especially in retrospect), but because I had
+*forgotten* that I setup 2FA for **personal**, I naively assumed this issue
+might magically disappear given enough time... kind of how restarting your
+device resets the state and causes the symptoms of a certain class of bugs to
+disappear.
+
+After a few days of mounting frustration, I decided to take a closer look...
+
+## Solution
+
+-   Create an "App Password" for **personal**:
+    [instructions](https://support.google.com/accounts/answer/185833?hl=en).
+-   Login to **work** and delete **personal** from `Settings > Accounts > Send
+    mail as`.
+-   `Add another email address` for **personal** using the "App Password" you
+    just created.
+
+And now I'm back in business!