Stop Using Images in Email Signatures

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It's Bloat

Filling emails with unnecessary images inflates their size wasting bandwidth and disk-space. For those who have limited amounts of either, it makes handling emails cumbersome. The additional time spent loading or transferring image-laden emails will make recipients, and anyone else who interacts with the emails (like IT professionals or archivists), despise the sender in direct proportion to the rampancy of the image-inclusion heedlessness.

It's Technologically Counter-Productive

Images are not Searchable nor Interactive

No consumer-oriented email client front-ends implement optical character and object recognition algorithms to facilitate searching for, or interacting with, image content. This means that text cannot be conveniently selected and copied, screen readers won't work for those that have accessibility issues, and the content isn't able to be easily modified without image editing software.

Images Behave Unexpectedly

Whether an image displays in its embedded form or as an attachment, and if embedded, whether it displays at all let alone with the correct size and aspect ratio, depends the email client front-end, the screen and the security settings used by the recipient. For example, more secure email clients like ProtonMail will not load images by default unless explicitly told to. Mobile devices commonly miniaturise images to the point of being almost impossible to view with any fidelity, or they reorder and reposition content usually to an undesirable location. Alternatively, to combat these issues, mobile devices will omit embedding entirely, opting for attachment instead.

Images are a Privacy and Security Risk

Each time one opens a linked (remote) image it has to be downloaded from some server before it can be displayed on the device. Often this is done automatically unless disabled by the email client front-end.

Whenever an image is downloaded, it implicitly tells the sender (e.g. a potential spammer or hacker) the IP address of the receiving device, that the email was delivered and opened successfully, and that the destination email was valid. To make matters worse:

  • Image requests via HTTP can set cookies in browsers which can then be used to track a user across the web.
  • Malicious code can be embedded in the "image" (remote or not) and potentially executed if viewed on the recipient's device.

By participating in the transmission of emails with unnecessary image content, one is normalising an attack vector that is inherently more difficult for security systems and professionals to protect and educate against, thereby increasing susceptibility to spam, phishing and other malevolent actions.

Attached Images Hamper Email Filtering

Whenever an image ends up as an attachment to an email (whether directly or indirectly via embedding), recipients will no longer be able to reliably filter or search for emails that contain attachments, as every email with an ill-formed signature now contains at attachment. The alternative might be to use a more complex filtering criteria (e.g. based on image size), or manually crawl through bulk messages; however, both of these options waste time leading to resentment for the sender.

The Purpose of Email Signatures

People shouldn't forget that the purpose of an email signature is to provide the following information (as necessary and ordered in a descending degree of relevance):

  1. Valedictory (the closing statement e.g. "Kind regards").
  2. Blank line.
  3. Preferred name to be used in future correspondence.
  4. Section break (e.g. --).
  5. Full name (including any pre- or post-nominal letters).
  6. Title/position and organisation.
  7. Alternative contact medium(s).
  8. Other extraneous information (e.g. location, schedule, relevant information like website links, general statements, announcements et cetera).
  9. Disclaimers (notices or warnings e.g. confidentiality, copyright, security et cetera).

All of this information can be provided in textual form which is:

  • lightweight (a few bytes of information versus the kB or MB required for images),
  • searchable,
  • interactive,
  • reliably easy to read regardless of the screen size, resolution or whether images can be viewed/downloaded in the recipient's email client front-end, and
  • poses no security risk (excluding website links).

Here is a template to get started:

Kind regards,

Preferred Name
--
Pre-Nominal First Last, Post-Nominal
Position | Organisation
Phone: +614 12 345 678
Email: first.last@email.me
Office 1-2, Building A
Mon-Fri, 0800-1700 hrs
website.com