Using Inline Search

Inline search provides an additional mechanism to filter emails after they have been downloaded and before they have been written to disk.

Inline Search v. In-place Search

FEC's In-place Searches are performed directly on the email server. In-place searches are generally very fast as FEC does not actually download the emails or make its own search index to be able to search them. Instead, it passes your search query to the email server and retrieves a list of the results for you to preview and/or acquire.

On the other hand, inline searches are offline searches that are executed against an in-memory searchable index that is created after the email message is downloaded. Inline searches are typically more powerful than in-place searches but take significantly longer to perform on an entire mailbox.

Inline Search Use Cases

Main use cases for inline search include:

  • Working around in-place search limitations of an email provider such as limited syntax or lack of in-place search support
  • Working around in-place search caps imposed by providers
  • Bringing search capabilities to a common denominator when acquiring mailboxes from multiple providers within the same project
  • Scanning emails for complex data points such as personally identifiable information (PII) using regular expressions

Inline Search Options

Exceptions will be treated as responsive (default: OFF) Choosing this option causes FEC to treat indexing/search exceptions as responsive. In other words, if the email and/or its attachments could not be searched, it would be treated as responsive and included in FEC's output.

Only metadata will be searched (default: OFF) Choosing this option causes FEC to not extract text but only use metadata. This can be used to speed things up if your inline search only relies on metadata such as dates.

Only parent email will be searched (default: OFF) Choosing this option causes FEC to skip indexing attachments of the email. This can be used if you wish to limit the search to the parent emails only.

Inline Search Syntax


In order to treat a term as a phrase, enclose it in double quotes. Example:

"contract dispute"

Field Searches

You can restrict your query to a specific field by typing the field name followed by a colon. Otherwise, the search will be performed on the contents field. All field names should be typed in lowercase. Example:


The following fields are supported:

Field Description
from The sender of the email.
to The recipient(s) of the email.
cc The carbon copy recipients of the email.
bcc The blind carbon copy recipients of the email.
subject Email subject.
attachmentnames Names of the attachments of the email.
messageid Message-ID of the email as defined in RFC 5322.
headers MIME headers of the email.
contents A combination of the extracted text and metadata of the email. If the option to include attachments in the inline search was selected, this field also covers the text and metadata extracted from the attachments of the email. This is the default field that is searched when no field is specified.
earliestdate The earliest timestamp identified within the email. If the option to include attachments in the inline search was selected, timestamps encountered in the attachments of the email are also taken into account.
latestdate The latest timestamp identified within the email. If the option to include attachments in the inline search was selected, timestamps encountered in the attachments of the email are also taken into account.
received The received date of the email if it has trace headers.
sent The origination date of the email.
fscreationdate Internal date or creation date server metadata where applicable.
fsmodificationdate Modification date server metadata where applicable.

Date Searches

Date searches are performed as follows:

sent:[2021/01/20 TO 2022/03/14]

The above query would search for emails whose origination date is between January 20, 2021 and March 14, 2022.

When higher precision is desired, timestamps can be provided in full including the time component in 24-hour format. In this form, the timestamps should be enclosed in double-quotes. Timestamps are specified in UTC.


sent:["2021/01/20 13:51:05" TO "2022/03/14 14:45:13"]

Boolean Operators

The AND, OR, and NOT Boolean operators are supported. When no Boolean operator is specified between terms, the AND operator is used. Boolean operators must be in all caps.

Regular Expression Searches

When performing regular expression searches, the regex pattern should be enclosed between forward-slash ("/") characters. Example:

/m[ae]ssage/ would find documents containing massage or message.

Wildcard Searches

The * wildcard serves as a multiple-character wildcard while the ? character serves as a single-character wildcard. Example:

pro?e would match prove and probe

exam* would match exam, examine, and example

Proximity Searches

Proximity searches can be performed using the ~n syntax. Example:

"contract dispute"~5 would search for instances where contract and dispute are within 5 words of each other.


Sub queries can be grouped using parentheses. Example:

(dispute OR conflict) AND contract

Grouping can also be performed within a field. Example:

subject:(vehicle AND theft) would search for documents where both vehicle and theft are present in the subject field.

Example Searches

"contract dispute" OR "intellectual property" OR inspect* searches for two phrases and a wildcard term in the default (contents) field.

subject:mike attorney searches for documents whose subject contains mike and the default field (contents) contains attorney. Because a Boolean operator is not specified, the AND is implied.

headers:/74\.([0-9]{1,3})\.([0-9]{1,3})\.([0-9]{1,3})/ AND "intellectual property"~2 searches for emails with IP addresses in their MIME headers that start with 74., and contain intellectual and property within two words of each other.

messageid:"" searches for emails with a specific Message-ID.

Layered Searches

It is possible to combine Inline Searches with In-place Searches and Differential Acquisitions. For instance, if target mailboxes are to be filtered using a date restriction as well as a set of complex keywords, the date restriction can be performed as an in-place search, which would reduce the data size very quickly, and the keyword search can be performed as an Inline Search within the same acquisition.

Supported Attachment Types

The following types of attachments are currently supported:

eml, msg, xls, xlsx, pdf, pptx, doc, rtf, docx, zip, tar, xz, lzma, gz, bz2, rar, 7z, deb, ar, a, lib, iso, vhdx, vhd, wim, swm, esd, vmdk, text-based files (e.g., txt, log, csv, tsv, etc.), HTML, xml

Are Documents OCRed?

FEC does not perform optical character recognition (OCR) on email attachments that are missing extractable text.

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