How to Manage Microsoft Outlook’s AutoComplete List

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Microsoft continues to improve the Outlook email client. There seems to be an increasing number of productivity tools built into the Outlook platform many people are not aware exist, nor do they know how to use them.

One of those tools is called the AutoComplete list.

The AutoComplete list, automatically maintained by Outlook, is used by both the automatic name-checking feature and the automatic completion feature. This list is also known as the nickname cache and is generated automatically when you send email messages from Outlook. The list contains SMTP addresses, LegacyExchangeDN entries, and display names for people to whom you have sent email previously.

The AutoComplete list for Outlook is specific to Outlook and does not share information with the Outlook Web app (OWA).

Limit to the number of entries

Outlook limits the number of entries that you can save in the AutoComplete list. After you reach this limit, Outlook uses an internal algorithm to determine the best names to remove from the list. It does this based on a usage weighting. Therefore, you may find some names unexpectedly removed from your nickname cache. There are two general approaches you can use to avoid this situation:

1. You can proactively remove AutoComplete list entries that you no longer need. This is the preferred approach.

To remove entries from the AutoComplete cache one entry at a time, follow these steps:

  1. Open a new email message.
  2. Type the first few characters of the AutoComplete entry that you want to remove.
  3. When the entry appears in the list of suggested names, move your mouse pointer over the name until it becomes highlighted, but do not click the name.
  4. When the “X” icon appears next to the highlighted name, click X to remove the name from the list, or press the Delete key on the keyboard.

2. You can increase the limit for the nickname cache. Because this configuration is untested, we do not recommend it.

There is a limit to the number of entries maintained in the AutoComplete list. For Outlook 2016, the limit is 1,000 entries.

How to enable the AutoComplete feature

If AutoComplete is not enabled on your Outlook, following are the steps to turn it on for Outlook 2010, Outlook 2013, and Outlook 2016:

  1. On the File menu, click Options.
  2. Select the Mail tab.
  3. Scroll approximately halfway down until you see Send messages. Make sure the Use Auto-Complete List to suggest names when typing in the To, Cc, and Bcc lines box is checked.

It is straightforward to manage your AutoComplete list. For a long time, I did not pay attention to the AutoComplete list and ended up sending a few emails to the wrong people. My recommendation is to go ahead and remove old email addresses or addresses you no longer use to keep your AutoComplete list clean.

What other Outlook tips and tricks have you found that help you be more productive with email? Leave your comments below.

Steve Anderson provides information to insurance agents about how they can use technology to increase revenue and/or reduce expenses. He speaks professionally to hundreds of agents each year on the future of technology, the social web, and how insurance agencies can establish their Internet presence.

Please note: I reserve the right to delete comments that are offensive or off-topic.

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8 thoughts on “How to Manage Microsoft Outlook’s AutoComplete List

  1. Scott, there is a way that I was going to include, but found it to be quite technical. Do a search and you should find the steps. The autocomplete list is actually contained in a specific file.

  2. I wish this would work for suggested contacts also as the x does not appear. I also have removed list from options to start fresh but it must be cached?

    We have a O365 user when I type her name it brings up a name of the retired employ as name of contact with the new persons email and we have found no solution to fix this.

  3. Thanks Steve I enjoy all your tips and often times think I should return one or more… hence this note.
    I use Quick Parts all the time in BOTH Outlook as well as Word (maybe more elsewhere but those are the programs we use constantly). They are easy to create and a few clicks you can send an email complete with snips and perfect formatting – as long as you have it perfect in your first email that you create the Quick Part with!!!
    I have created a video for Outlook for my counterparts @ WAHVE – they are a bit more informative to see it in action – as well as my Word doc with the steps. I use it in Word when I do my Training Notes for my AMS360 trainings as well.
    Pretty slick tool!!!
    Again thanks for your tips and when I come across another I’ll shoot it to you.

  4. Are you aware of a way to filter the auto complete list? An example is I know that the is the domain but I don’t remember the person’s name or email name format? Is there a ‘filter’ or trick to ask autocomplete to find anyone with

  5. I wish there is a way to view the list and edit it. Otherwise, if I want to remove unwanted names, I first have to know who they are.

  6. Removing old and unused email addresses so that Auto-complete possibilities are more refined is a great practice.

    However – I think it still comes down to being efficient but also methodical when sending emails – In the past, I’ve been in too much of a hurry and mistakenly sent an email to “” when I meant to send it to “”. Auto-complete won’t help with that.