This document describes how I can read mail without relying on the outlook web interface, or Mac's mail app. This is somewhat complex because the university mail uses Microsoft exchange.

Mainly, the information below is compiled from this blog post, which describes davmail, and this post, which describes mu4e (emacs) configuration.

I got all of the software from brew. The packages required are davmail, isync (which provides the mbsync executable), and msmtp.

davmail is a program which acts as a proxy between Microsoft Exchange and IMAP/SMTP. The local machine's mail client connects to a local IMAP/SMTP server controlled by davmail, so that it doesn't have to talk to Exchange directly.

davmail has a configuration file, which is, in my case, at ~/.davmail.properties. Its contents are as follows:

# Disallow access to the davmail server from remote hosts (i.e.,
# other computers on the network)
davmail.allowRemote=false


# Don't use SSL (between email client and davmail)
davmail.ssl.nosecurecaldav=false
davmail.ssl.nosecureimap=false
davmail.ssl.nosecureldap=false
davmail.ssl.nosecuresmtp=false


# The ports to run the different services on. You'll need
# these to connect clients.
davmail.caldavPort=6000
davmail.imapPort=6001
davmail.ldapPort=6002
davmail.smtpPort=6003


# Connection details for your exchange account. Odds are good
# that the url listed here will work for you. If not, see if your
# University/employer has any details on the correct host URL to
# connect to their email services with.
davmail.url=https://outlook.office365.com/EWS/Exchange.asmx


# Set the authentication mode to manual
davmail.mode=O365Manual


# Run davmail in server mode
davmail.server=true
davmail.enableKeepAlive=true

Once a program, like mbsync, which reads mail into a local mailbox on your machine, connects to the IMAP server (which, again, is run locally through the proxy established by davmail), davmail reaches out via exchange, and will produce a URL. This URL leads you through an authentication flow finally resulting in a blank page whose URL contains the authentication token. Passing this URL back into davmail authenticates it with exchange. Once it's authenticated, the aforementioned config file is modified with a line containing the token:

...
# Run davmail in server mode
davmail.server=true
davmail.enableKeepAlive=true
davmail.oauth.<my email>.refreshToken=<the token>...

In my case, there was one hitch, which is that the canonical input processing mode prevented me from pasting the entire token since it's so long. So, I had to disable canonical mode when running davmail, so that the token would be sent to the process in its entirety:

$ stty -icanon && davmail ~/.davmail.properties

mbsync is used to download mail from the mail server. My configuration file is located at ~/.config/isyncrc, and its contents are as follows: (I've replaced my actual account name with <account name> and my email with <my email>).

IMAPAccount <account name>
Host 127.0.0.1
Port 6001
User <my email>
PassCmd "security find-generic-password -a umail -s mbsync -w"
TLSType None
AuthMechs LOGIN

IMAPStore <account name>-remote
Account <account name>

MaildirStore uchicago-local
Path ~/Mail/<account name>-mail/
Inbox ~/Mail/<account name>-mail/INBOX
SubFolders Verbatim

Channel uchicago
Far :<account name>-remote:
Near :<account name>-local:
Patterns *
SyncState *
Create Both
Sync All
Expunge Near

PassCmd is a command to run to find your account password. We can use macOS' security command to call up the password from keychain when it's required, rather than writing it in plain text in the configuration file.

Running mbsync <account name> will sync the local mail directory specified as above with the server.