Your main Inbox looks empty, senders swear they wrote to you, and nothing reports an error. Before changing a single setting, answer the one question that decides everything: where is the mail actually landing? In the large majority of post-PST-change cases it is arriving complete - into the Inbox of a second data file you forgot was in the profile. This page finds it with evidence, not guesswork.
The discipline is simple: do not fix before you locate. Every "not receiving" complaint splits into two families - mail that never reaches the PC, and mail that reaches Outlook but is filed somewhere unexpected. The tests below separate them in about five minutes, and they need nothing but the folder pane, one honest search, and your webmail login.
Example folder pane. One Inbox shows zero unread while a second file, added during the PST change, quietly collects everything. The bold number is the confession.
The folder pane only shows what you expand. After a PST change there are often two or more data files in the profile, and the second one hides below the fold of the pane.
Outlook prints a bold number beside a folder holding unread mail. If your working Inbox shows no number while a strange Inbox grows one every day, the case is solved: mail is arriving perfectly - into the other file. Open that Inbox and check the dates. If the newest message matches the day your mail "stopped", you have confirmation, not a guess.
Search is the honest referee, but only if you give it the whole field:
Before blaming Outlook for anything, establish what the server holds. Open the mailbox in a browser. If the new mail is on the server but in no local folder, Outlook is failing to bring it down - a sync or Send/Receive problem. If it is not on the server either, the problem is not Outlook at all: check the sender address, the server junk folder, and whether the mailbox is full. For POP accounts that do not leave a copy on the server, remember the reverse: once Outlook has downloaded a message, it may exist only in the local file - which is why finding that file matters so much.
The full fix, shown live in Outlook - the account settings screens, the delivery location and the test mail arriving - is in the video above.
Watch Full VideoUsually a filtered view. Open that folder, then go to View and choose Reset View - a leftover filter can hide messages that are really there. Also check the folder is sorted by Received date, newest first; mail sorted by sender or size can look absent when it is simply not where your eye expects it.
That folder genuinely holds unread mail the current view is hiding. Reset the view as above, and remove any search filter text from the Search box. If the count survives a view reset and the folder still looks empty, the data file itself may be damaged - work on a copy of the PST and check it with the Inbox Repair Tool before trusting it further.
That is the other family: Outlook is not bringing mail down at all. Run Send/Receive and read the progress window for errors, and check the status bar for Work Offline. The delivery-location guides in this series will not help until mail actually reaches the PC again.