AusDoc SOLUS eDM SPECIFICATIONS

Find out specs and dimensions specifically for our range of SOLUS eDMs we send to our highly engaged audience.

AusDoc manages the entire delivery process — reviewing, testing, and scheduling the client’s supplied HTML file

This document outlines the technical specifications required for submitting a Solus Email and provides best practice guidelines to help you brief designers, developers, or vendors effectively

Lead Time & Approval Process

Final HTML files, subject heading and preview text must be received 10 days prior to the booked send date.

A test email will be sent to your nominated test recipient list for approval prior to distribution.

File Requirements

File Type: .html or .txt file of the HTML code (PDF or image only files are an incorrect format and cannot be accepted. Many email providers block images by default)
Layout: Table based and mobile responsive
Styles: Inline CSS styling needs to be included on HTML elements
Width: Max 600 pixels
Height: No pixel limit
File size: ≤ 150 KB limit
Content Types: Images and text only (no embedded forms, attachments, or videos always link externally)

Image Specifications

Hosting: Externally hosted with absolute URLs
Format: JPG / PNG / GIF
Resolution: 72 DPI (web optimised)
Width: Max 600 pixels (export 2×–3× for retina clarity)
Alt text: Required for accessibility
File size: ≤ 200 KB each (total images ≤ 1 MB)
Linking: Reference images with https://

HTML Meta Inclusions

Doctype:

<!DOCTYPE html> <html lang="en" xmlns="http://www.w3.org/1999/xhtml" xmlns:v="urn:schemas-microsoft-com:vml" xmlns:o="urn:schemas-microsoft-com:office:office">

Include the following metatags in the section of your HTML:

<meta charset="UTF-8"> 
<meta name="viewport" content="width=device-width, initial-scale=1.0"> 
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<meta name="x-apple-disable-message-reformatting"> 
<!--[if gte mso 9]>
<xml> 
<o:OfficeDocumentSettings>
<o:AllowPNG/>
<o:PixelsPerInch>96</o:PixelsPerInch> 
</o:OfficeDocumentSettings>
</xml> 
<![endif]-->

Header & Footer

Include the supplied AusDoc header and footer within your HTML file upon submission

Subject Heading & Preview Text

Subject Heading Length: Within 40–60 characters (approx. 6–9 words)

Preview Text Length: Within 35–90 characters (key message within first 70)

Tags & Links

Type: Use Full / Absolute URL (do not use partial URL links)
Tracking: You can use UTM tags attached to links (optional)
Software: Link management software is not recommended as it may get flagged by email providers
Testing: It is recommended to test your links prior to submission (especially if you have added UTM tags to the end of the URL)

Best Practice Recommendations

1. Layout & Structure

Keep it to 1-2 columns (totaling 600 pixels wide) as it scales best across Outlook, Gmail, and mobile clients

Lead with clarity: Place logo, headline, and/or hero image at the top for instant recognition

Prioritise the primary CTA: It should appear within the top 400 pixels and again near the end for scannability

Use whitespace intentionally: Improve scan flow and highlight key messaging without clutter

Avoid text heavy or stacked/overlaid images: They often break in Outlook and increase load time

Maintain sufficient text-to-background colour contrast: WCAG AA / AAA standard

Maintain ~60 % text / 40 % image ratio: Ideal for spam filter balance and prevents email provider image block

Avoid all-image emails: Many email clients block images by default, so if your email is made entirely of images, it may appear blank when opened

2. Content, Text & Readability

Front-load key information: Busy medical professionals skim; ensure the first 2 lines deliver the value

Use short paragraphs and bullet points: 1-2 sentences per block/section to maintain the viewers attention

Write in plain, factual English: Avoid marketing superlatives; focus on clarity and credibility

Subject line + preview text combo: Under 50 characters each, together should tell a clear story

Header text in images must also exist as live HTML text: Ensures accessibility and indexing

Minimum font sizes: 14 pixels body / 20 pixels headings for legibility and accessibility

3. Calls-to-Action (CTA’s)

Primary CTA button: Use a clear, action-focused verb (e.g. Register, Learn More, Download) and position the button in logical, high-visibility locations ideally near the top of the email. Include the CTA multiple times where it supports user decisionmaking and encourages conversion

Secondary CTA button: Position lower than a primary CTA in the email and/or style differently to indicate a supplementary, less critical action. This supports additional engagement without distracting from the primary goal

Minimum button size: 44 × 44 pixels (touch friendly)

Keep it focused: One primary goal per email improves clarity and click through performance. A clear, user centred value proposition with a balanced number of buttons enhances overall engagement and usability