Outlook is not creating a stream_autocomplete file

Question

Hi,

I’m trying to set up outlook with my google email account over imap and I cannot get autocomplete to work at all.

I’ll send an email the previous day and the auto complete with not work after closing and re opening outlook.

I’ve tried unchecking the auto fill tick box in the options restarting and ticking it again and restarting and it still will not autofill.

I’ve tried the clear autofill with no luck.

I’ve tried deleting the roamcache folder and the restarting and it still will not create a stream_autocomplete file.

I have also tried reinstalling m365 from scratch and deleting the roamcache file and it still will not create a stream_autocomplete file.

Has anyone had any luck with an issue similar to this before?

Thanks,

[Moderator Note: Personal Info Removed]

Answer 1

Hi Alex Betts,

Thank you for reaching out to Microsoft Q&A forum.

Please note that our forum is a public platform, and we will modify your question to hide your personal information in the description. Kindly ensure that you hide any personal or organizational information the next time you post an error or other details to protect personal data.

From your description, I understand that you are experiencing an AutoComplete incident when your Gmail account is connected via Internet Message Access Protocol (IMAP) in Classic Outlook for Windows.

For accounts that use Internet Message Access Protocol (IMAP), Outlook does not rely on the stream_autocomplete*.dat file inside the RoamCache folder. The AutoComplete list is stored inside the Outlook data file as a hidden item named IPM.Configuration.Autocomplete. Because of this design, recreating the RoamCache folder alone does not produce a stream_autocomplete file.

Please follow the definitive remediation steps below:

Step 1: Verify and refresh AutoComplete settings

• Open Outlook and select File > Options > Mail.
• Under Send messages, ensure “Use Auto‑Complete List to suggest names when typing in the To, Cc, and Bcc lines” is enabled.
• Select Empty Auto‑Complete List to refresh the cache.

Step 2: Open Outlook in Safe Mode and rule out add‑ins

• Open Safe Mode by using Run:
  • outlook.exe /safe
• When prompted, choose Yes to open Outlook in Safe Mode.
• If AutoComplete suggestions are consistent in Safe Mode, disable third‑party add‑ins:
  • Outlook > File > Options > Add‑ins
  • At the bottom, select Component Object Model (COM) Add‑ins > Go…
  • Uncheck non‑Microsoft add‑ins > OK
  • Close and reopen Outlook normally and validate again.

Step 3: Rebuild the RoamCache folder (clean start)

• Close Outlook completely.
• Open Run and navigate to the Outlook local data folder:
  • %LOCALAPPDATA%\Microsoft\Outlook
• Rename the RoamCache folder to RoamCache_old.
• Reopen Outlook; a fresh RoamCache folder will be created automatically.

Step 4: Repair the data file with the Inbox Repair Tool

• Use the Inbox Repair Tool (SCANPST.EXE) from the Microsoft Office installation folder (example path):
  • C:\Program Files\Microsoft Office\root\Office16\SCANPST.EXE
• Select the Outlook data file for your Gmail Internet Message Access Protocol account — either Offline Storage Table (OST) or Personal Storage Table (PST) — and choose Repair.
• Open Outlook and validate AutoComplete suggestions.

Step 5: Create a new Outlook profile (clean baseline)

• You can open the Mail applet in Control Panel either by navigating through Control Panel > User Accounts > Mail (Microsoft Outlook), or by using Run:
  • control mlcfg32.cpl
• Select Show Profiles > Add… to create a new profile.
• Re‑add your Gmail account through Internet Message Access Protocol (IMAP).
• Open Outlook and send a few messages to seed the new AutoComplete list.
• After confirming stability, set the new profile as Default.

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