Convert EML to POTM in C# .NET

What is EML file format?

The EML file is a type of email message that includes both the message content and the email header information. It is an extension of the Mime (Multipurpose Internet Mail Extensions) format and is used in most email clients, including Microsoft Outlook and Mozilla Thunderbird. EML files are used to save an email message before it is sent and can also be used to archive emails. The EML file format is an XML-structured file that is used to store the header information, such as sender, recipient, subject line, and date, as well as the message content, such as body text, HTML, images, and attachments. The header information is stored in the header of the file and the content is stored in the body. The file is readable by both humans and computers, and can be opened in a text editor, such as Notepad or TextEdit. EML files are commonly used to transfer emails between different email systems. For example, when an email is sent from one email client to another, the email is usually saved as an EML file and then transferred over the internet. This ensures that the message is delivered properly. The EML file format is also used to store emails in an archive. For example, emails can be archived in an EML file and then later opened and read in any compatible email client. This makes it easy to keep emails organized and backed up. In addition to being used for email messages, the EML file format is also used by some applications to store log files, document files, and other types of files.

What is POTM file format?

A POTM file refers to a macro-enabled presentation template created using Microsoft PowerPoint, a software program used for creating slide show presentations. It includes default images, slide templates, macros, and formatting. POTM files are commonly used by PowerPoint users to create multiple .PPTM files with consistent designs and macro settings.

POTM files offer additional functionality compared to typical presentation files, as they support macros. Macros are script-like functions that automate repetitive tasks within PowerPoint. Users can record macros that can be replayed to perform specific actions and assign them to buttons or keystrokes for convenient execution. To record a macro, users can select View → Macros in PowerPoint.

For general presentation creation, users can save their files as .PPTX or .POTX files. However, if they want to create a template that incorporates macros, they can save their presentation as a POTM file.

It’s worth noting that POTM files were introduced by Microsoft when they released Microsoft Office 2007.

To open a POTM file, Microsoft PowerPoint (2007 or later) is the recommended application for full support of presentation formatting and embedded macros on both Windows and macOS. Alternative applications like Apache OpenOffice Impress, Kingsoft Presentation, and Apple Keynote can also open POTM files, but some formatting and macros may not be fully preserved. For Mac users looking to view a POTM file without editing, Apple Preview (bundled with macOS) or Google Drive, a free cloud storage service, can be used.

Online platforms like Google Slides allow users to upload POTM files for viewing, editing, and conversion. However, it’s important to note that Google Slides does not support macros.

To convert a POTM file, various presentation applications including Microsoft PowerPoint, Apple Keynote, and OpenOffice Impress offer conversion capabilities. In Microsoft PowerPoint for Windows and Mac, users can select File → Save As and choose from formats such as .PPTX, .PPT, .PDF, .ODP, .XPS, .MP4, .WMV, .JPEG, and .PNG to convert the POTM file to their desired format.