SIG File Extension

SIG file icon
Signature Format

What is SIG file?

SIG file contains a digital signature saved in text format, which can be attached to, for example, a n email or Usenet message. Initally SIG files were used for email messages to avoid the need to sign it with the same text each time a new message was created. Currently, depending on the application, SIG file can contain HTML- formatted data or images.

Signature typically consists of:

  • Name and surname or nickname/alias,
  • Contact data – email address, telephone number, address,
  • Post or job title, especially for work-related messages,
  • Quotes, graphical elements, logo.

SIG file can be created using an email client or manually with text editor. Signature is added to the end of message, in the footer.

Programs which support SIG file extension

The list that follows enumerates programs compatible with SIG files, divided into 2 categories based on operating system on which they are available. SIG files can be encountered on all system platforms, including mobile, yet there is no guarantee each will properly support such files.

Programs that support SIG file

Updated: 06/24/2020

How to open file with SIG extension?

Problems with accessing SIG may be due to various reasons. Fortunately, most common problems with SIG files can be solved without in-depth IT knowledge, and most importantly, in a matter of minutes. The list below will guide you through the process of addressing the encountered problem.

Step 1. Download and install Eudora

Install software to open SIG file The main and most frequent cause precluding users form opening SIG files is that no program that can handle SIG files is installed on user’s system. This one is an easy one. Select Eudora or one of the recommended programs (for example, Microsoft OneNote, Microsoft Outlook, Microsoft Outlook Express) and download it from appropriate source and install on your system. On the top of the page a list that contains all programs grouped based on operating systems supported can be found. One of the most risk-free method of downloading software is using links provided by official distributors. Visit Eudora website and download the installer.

Step 2. Check the version of Eudora and update if needed

Update software that support file extension SIGYou still cannot access SIG files although Eudora is installed on your system? Make sure that the software is up to date. Software developers may implement support for more modern file formats in updated versions of their products. This can be one of the causes why SIG files are not compatible with Eudora. All of the file formats that were handled just fine by the previous versions of given program should be also possible to open using Eudora.

Step 3. Set the default application to open SIG files to Eudora

If you have the latest version of Eudora installed and the problem persists, select it as the default program to be used to manage SIG on your device. The method is quite simple and varies little across operating systems.

Associate software with SIG file on Windows

Change the default application in Windows

  • Clicking the SIG with right mouse button will bring a menu from which you should select the Open with option
  • Click Choose another app and then select More apps option
  • Finally select Look for another app on this PC, point to the folder where Eudora is installed, check the Always use this app to open SIG files box and conform your selection by clicking OK button
Associate software with SIG file on Mac

Change the default application in Mac OS

  • From the drop-down menu, accessed by clicking the file with SIG extension, select Information
  • Proceed to the Open with section. If its closed, click the title to access available options
  • From the list choose the appropriate program and confirm by clicking Change for all....
  • If you followed the previous steps a message should appear: This change will be applied to all files with SIG extension. Next, click the Continue button to finalize the process.

Step 4. Verify that the SIG is not faulty

If you followed the instructions form the previous steps yet the issue is still not solved, you should verify the SIG file in question. Being unable to access the file can be related to various issues.

Check SIG file for viruses
1. Check the SIG file for viruses or malware

Should it happed that the SIG is infected with a virus, this may be that cause that prevents you from accessing it. Immediately scan the file using an antivirus tool or scan the whole system to ensure the whole system is safe. If the scanner detected that the SIG file is unsafe, proceed as instructed by the antivirus program to neutralize the threat.

2. Ensure the file with SIG extension is complete and error-free

If the SIG file was sent to you by someone else, ask this person to resend the file to you. During the copy process of the file errors may occurred rendering the file incomplete or corrupted. This could be the source of encountered problems with the file. It could happen the the download process of file with SIG extension was interrupted and the file data is defective. Download the file again from the same source.

3. Verify whether your account has administrative rights

There is a possibility that the file in question can only be accessed by users with sufficient system privileges. Switch to an account that has required privileges and try opening the Signature Format file again.

4. Check whether your system can handle Eudora

The operating systems may note enough free resources to run the application that support SIG files. Close all running programs and try opening the SIG file.

5. Check if you have the latest updates to the operating system and drivers

Up-to-date system and drivers not only makes your computer more secure, but also may solve problems with Signature Format file. It may be the case that the SIG files work properly with updated software that addresses some system bugs.

Do you want to help?

If you have additional information about the SIG file, we will be grateful if you share it with our users. To do this, use the form here and send us your information on SIG file.

Top File Extensions
Show more
File Extension of the day
ctg icon


BMC Software PATROL Format

CTG file contains user-defined events catalog used by PATROL tool developed by BMC. CTG is a text file with strictly defined structure. CTG files a...