Professors receive a lot of email, and professors are notorious about ignoring emails (if I recall well, a piece advice in one of Cal Newport's books is to treat email like a professor - just don't reply if it's not worth it). After a two-week holiday, I once had over 70 requests to review an article, and over 1000 messages to sieve through. It's easy to get absorbed into your mailbox the entire day. It's also easy to start feeling overwhelmed.
Dealing with email in a way that still leaves me time for my research has been one of my main challenges over the past years. I'm not at a point where I can say that I manage to keep on top of my mailbox and get everything done at the same time, but I've made some good progress.
Here's what I've learned over the past years:
1. Inbox Zero
I do a modified version of the regular Inbox Zero. I don't always have an Inbox Zero, I certainly don't end every day with an Inbox Zero, and I don't immediately archive and plan every thing. What I do, however, is to archive emails and delete them after dealing with them. I strive to get down to zero, but my backlog can go up to 600 emails to process (or more, after a holiday).
2. Track it
I want to do a better job in dealing with requests within a reasonable amount of time, so one thing I track every day in my bullet journal is the number of emails I start the day with and the number I end the day with (and unfortunately there are bad days when the latter is higher than the former), as well as the difference between end of the day and beginning of the day.
3. Block time
In my weekly template, I put time every day for dealing with email and admin. I typically schedule 1 - 1.5 hours per day, and often do some additional email-replying at the end of the day after my daughter sleeps. With this daily time block, I manage to do some progress every day.
4. List with color code
Every Friday, when I make my planning and list of priorities for the next week, I go through my mailbox and make a list of all pending items in there. I use a color code: green for service, purple for contacts and collaborations, brown for blog-related issues, orange for personal emails, black for projects, pink for papers in progress and light blue for teaching and MSc students. I try then to organize my time so that I can tackle all teaching related emails together, and address paper-related emails by setting aside writing time to edit and work on the paper that is in the email.
5. Put it on your calendar
As I mentioned in the previous part, when you divide the emails in topics, you can put these different topics on your calendar. I've found it more productive to deal with emails per theme or topic, rather than just try to reply them in order that they appear in your mailbox. If I reply in order, I will typically order them per subject of the email, rather than in chronological order.
6. Clean up time block
If all else fails, I plan in a larger time block (or even a few days), to deal with all pending items. If I recall well, I needed 6 weeks after my maternity leave to clean out everything and get back up to speed. After a holiday, I usually need the first few days to get through everything. If I've been absorbed by a project, I also usually need to schedule a few bigger time blocks to catch up with all pending emails.