You set up the new profile, your mail and contacts arrive - but the To field suggests absolutely nobody, and it feels like something failed to migrate. Almost certainly, nothing failed. A new profile starts with an empty AutoComplete memory by design. Here is why, and your two honest options: let it rebuild, or transplant the old one.
This is the single most common autofill panic: new profile or new PC, empty suggestion list. Technicians create new profiles to fix other Outlook problems, users create them on new laptops - and both then chase the blank To field as if it were a second fault. It is not a fault. It is how the profile-based cache works, and this page explains the mechanics and the realistic timelines.
An Outlook profile is a container: accounts, settings and the AutoComplete cache all belong to it. When you create a new profile - on a new PC, after a repair, or to fix a corrupted old profile - it starts with a brand-new, empty Stream_Autocomplete file. Your mail arrives because it lives on the server; your contacts arrive because they sync or are imported; your suggestion list does not arrive, because for IMAP and POP accounts it was never anywhere but the old profile's local cache. Nothing has gone wrong. You are watching a memory that has not been built yet.
There is one honest exception. For Exchange-based accounts, the AutoComplete list is stored inside the mailbox, not in the local profile. A new profile for such an account should repopulate its suggestions once the mailbox has fully synced - give it time, keep Outlook open, and do not judge in the first ten minutes. If a Microsoft 365 profile still shows an empty list after a complete sync and a restart, that is a genuine problem worth the cache checks in our main fix guide.
AutoComplete learns from sending, not from receiving. Every address you send to joins the list immediately, so the rebuild follows your real habits: the people you email daily are back on day one, weekly contacts within the week, and the rare ones whenever you next write to them. Reading old mail does not teach it, but replying does. In practice, most users stop noticing the empty list within a few working days - which is why, for a healthy new profile, patience beats every technical trick.
If the old profile or old PC is still available, the list can be transplanted instead of rebuilt. The documented method copies the old Stream_Autocomplete cache file from the old RoamCache folder into the new one and renames it to match the new profile's file - with Outlook closed on both sides. Our moving guide walks through it step by step, including the backup habit that makes the next move painless. One warning: do this before you start heavily using the new profile, because the transplant replaces whatever the new profile has learned so far.
Watch the video before you create that new profile - the two minutes spent copying one cache file are the difference between a smooth move and a week of typing full addresses.
▶️ Watch Full VideoYou did not break anything. The AutoComplete cache belongs to the profile, so the new profile started empty while the old profile still holds its list in the RoamCache folder. If the old profile's cache file is still on disk, the transplant method can move it across - see the moving guide linked from this page.
For most people, two to five working days. The list learns from every email you send, so your frequent contacts return almost immediately and the long tail fills in as your normal work cycles through it. There is no setting that speeds this up - only sending mail teaches the list.
That one is not the expected pattern. Exchange-based accounts store AutoComplete in the mailbox, so after a complete sync and an Outlook restart the suggestions should be present. If they are not, work through the setting check and cache restart in our main autofill fix guide - for these accounts the problem is real and fixable.