Boolean Search Syntax

  • * Operators and functions must be CAPITALIZED (e.g. AND, OR, NOT, ALL, ATLEASTONE, NEITHER, NOTALL)
  • * Special characters are: `! @ # $ % ^ ( ) - = ~ + [ ] { } ( ) | " ' : ; . , < > ? / 1 2 3 4 5 6 7 8 9 0
  • * Spaces are special characters
  • * Keywords containing special characters or phrases containing two or more words should be enclosed in quotes (e.g. "#searchpst", "Outlook 2019", "email pst file", "search-utility")


Note that operators and functions must be CAPITALIZED, otherwise they will be treated as a query keyword. Query operators must also be preceded and followed by query keywords or query phrases.

AND operator

The AND operator may be used to find emails containing both specified keywords.


Outlook AND keyword  finds "Outlook search keywords", "how to search keywords in Outlook"

OR operator

The OR operator may be used to find emails containing either of two keywords.


best OR fast finds "best Outlook search tool", "fast search Outlook"

NOT operator

The NOT operator excludes any emails containing the keyword which follows it.


folder AND NOT email finds "search all folders in Outlook", but not "search all folders and emails in Outlook"

ALL function

The boolean function ALL(keyword1, keyword2, ..., keywordN) is equivalent to keyword1 AND keyword2 AND ... AND keywordN


ALL("boolean search", "excel-like filtering", "instant search")


The boolean function ATLEASTONE(keyword1, keyword2, ..., keywordN) is equivalent to keyword1 OR keyword2 OR ... OR keywordN


ATLEASTONE(best, free, download)

NEITHER function

The boolean function NEITHER(keyword1, keyword2, ..., keywordN) is equivalent to NOT keyword1 AND NOT keyword2 AND NOT ... AND NOT keywordN


NEITHER(email, message, contact, notes, appointment)

NOTALL function

The boolean function NOTALL(keyword1, keyword2, ..., keywordN) is equivalent to NOT keyword1 OR NOT keyword2 OR NOT ... OR NOT keywordN


NOTALL(Outlook, Thunderbird, Outlook Express, "Windows Mail")


Search queries can use parentheses to control the logic of the query and they may appear in any combination. Every left parenthesis must have a corresponding right parenthesis. Queries can have nested parentheses.


(search AND multiple AND (emails OR words))


A wildcard characters in a query may be used to searching for multiple items with similar, but not identical data. It allows to search all spellings of the keyword.

* character

Matches any number of characters. You can use the asterisk (*) anywhere in a character string.


search* finds search, searching, searches, searched

? character

Matches a single alphabet in a specific position.


"Outlook 201?" finds "Outlook 2019", "Outlook 2016", "Outlook 2013", "Outlook 2010"

See Also

How to use PST Walker

This guide explains how to open, find and extract emails from .pst files and .ost files with portable PST Viewer.

Sort and group email files and messages

Sort, arrange and group your email files and messages in a way that's helpful to you. For example, group by the name of the sender or the recipient and sort by the date of the email message, its size, and other options.

Search multiple .pst and .ost files without Outlook

Boolean search, Excel-like filtering, instant search. Supports any .pst and .ost files: corrupted, orpah, archive, password protected and encrypted files. Export search results to numerous formats. MAPI properties explorer.