Published: 24 January, 2024

The ‘Outlook Lines’ bug

Occasionally, you may notice your template has thin 1-pixel horizontal lines through it. This is due to a known bug with certain versions of Outlook, and are a result of the way Outlook displays HTML. This affects anyone sending responsive HTML emails, not just ProFundCom.

There is no hard & fast rule about why they appear, but users have found that simply adjusting the spacing and font sizes can often make them disappear entirely. Each block in the Drag & Drop editor has a ‘vertical spacing’ option – you can try adjusting this by a few pixels and see if it makes a difference. Many blocks also have their own internal spacing which can be similarly adjusted.

New ‘Body Background’ editor feature

Previously if this did not solve the issue, there wasn’t much that could be done. However, we have recently added a new feature which can help to mitigate these lines if adjusting the spacing does not work.

In the editor you’ll find a new setting in the page options:


If you turn it on for a template a new menu panel will appear:


Here you can choose from a few options for the colour of the <body> background in your template. Previously this was always set to white, with the blocks laid on top of it to create the external background colour chosen in the editor – it’s this white colour that bleeds through between the blocks and creates the white lines bug.

So for example if your template is largely dark blue, you can set the Body Background to the same colour and if the lines bug appears, they’ll be in the same dark blue and won’t be noticeable.

If you change this option, you won’t see any immediate changes in your template, as the area it affects lies under the added blocks. But the new panel has its own preview to show the colour chosen.

You can pick:

  • white – the original default behaviour. If you don’t switch on the Body Background options, this is what will be used.
  • the default Internal/External colour. This is the default background colour new added blocks have before any styling is applied. The ‘Internal’ background is the inside of the block where the content lies, the ‘External’ background is the colour that lies to the left and right of the block, outside the document’s borders. If you wish these default colours to be changed, you can ask on the Helpdesk.
  • the most used Internal/External colours in the current template – this counts the background colours used in the blocks you’ve added so far, and sets the Body Background to the ones used the most.
  • or you can choose ‘custom colour’ and pick a specific colour.

What difference will I see?

On most email clients you’ll not notice any difference. If you use the Delivery Studio to preview your template on all the major email clients, you may notice that on some devices your template has a thin border in the colour chosen – you’ll need to decide whether this is an acceptable compromise. Generally if the aim is to colour the bugged lines to make them unnoticeable, you’ll be choosing the existing background of your template anyway so this thin border will likely not be an issue.



Find out how ProFundCom can help you

Sign up for a 3 month trial. We’ll help you get going and answer any questions.

Try now