How to prevent Apple Mail from removing images on replying

Problem:

When you reply (or your recipient replies) to an email in the Apple Mail app, images in the email body are removed from the original message and then replaced with filenames surrounded by angle brackets like <logo.jpg>, <banner.png>, or <image001.jpg>. This also applies to images included in an email signature.

If you or your recipient doesn’t reply to the email, all the images display just fine.

Solution:

This issue is characteristic of the native mail app for iOS and cannot be attributed to an email system (e.g. Exchange Online) or third-party software (e.g. CodeTwo email signature tools) whatsoever. The reason is the Mail app’s feature that tries to remove all attachments in the reply, such as:

• standard email attachments (e.g. PDF, PPTX, or XLSX files),
• inline email attachments (e.g. email signature images embedded in email body, screenshots pasted into email body, etc.),

to reduce the size of the entire email thread.

Here’s what exactly happens when the Reply button is used in the Mail app on Mac, iPad, or iPhone:

Video: Mail app removes the images on replying to an email.

Minimize the impact with an HTML trick

We recommend that you start from minimizing the impact on your end. You can use the following HTML trick to make the resulting filenames of images in your email signatures so small that they become invisible to recipients, without corrupting the signatures’ layout. The solution works in both light and dark modes.

1. Sign in to the Signatures app and open your email signature template for editing – move the mouse over the signature preview and click Edit signature (Fig. 1.).

Fig. 1. Opening an email signature for editing.

2. In the editor, click HTML source on the ribbon to access the signature’s HTML source code.
3. Click Find text and type <img to find the first instance of an image in the signature’s code (Fig. 2.).

Fig. 2. Locating the first image in the signature’s HTML code.

4. If the image:
   1. Is not linked (there is no <a href=…> tag preceding the <img> tag), add the following <span> element around the <img> tag:

      <span style="font-size: 0.1pt; color: rgb(255, 255, 255);"><img src=…></span>

      as shown in Fig. 3.

      
      Fig. 3. The <span> tag added around the <img> tag (the image).

   2. Is linked (the <img> tag is put inside the <a></a> tags), add the following style attribute inside the opening <a> tag:

      style="font-size: 0.1pt; color: rgb(255, 255, 255);"

      as shown in Fig. 4.

      
      Fig. 4. The style attribute added to the <a> tag.

5. Locate next <img tags in your email signature by using the Find text feature and repeat step 4 for each of them.
6. If you’re using the {Photo} placeholder to add Microsoft 365 user photos to your email signatures (learn more), add the following style attribute inside the tag that directly precedes the {Photo} placeholder (in our example, it’s <span>):

   style="font-size: 0.1pt; color: rgb(255, 255, 255);"

   as shown in Fig. 5.

   
   Fig. 5. The style attribute added to the <span> tag right before the {Photo} placeholder.

7. Once all the images in your signature have been updated as shown above, click Apply & Close to close the HTML source code view (see the top left corner of Fig. 5.), and then click Publish & Close to close the editor and save your changes.

Now, if your recipient uses Apple Mail and replies to an email with the signature you’ve updated, the signature will look as shown in Fig. 6., item A. Without modifying your HTML code, the same signature would look as shown in Fig. 6., item B – with filenames of removed images all around.

Fig. 6. A reply in Mail – with the HTML trick applied (A) and without applying the HTML trick (B).

Ways to fix the problem

Next, if you wish to get rid of the problem completely, use one of the 2 solutions listed below:

• Use linked images instead of embedded ones
• Switch to Outlook for iOS

Use linked images instead of embedded ones

The advantage of this solution is that you and your recipients can continue using Apple Mail. It is especially useful if the problem affects recipients outside your organization, and you have no control over what email app they use (e.g. they do not want to switch from Mail app to e.g. Outlook for iOS).

Unlike embedded images, linked or online images are not considered attachments but references to images located externally, on a web server. When designing your email signature, you do not technically include these images in it. Instead, you provide web addresses to where they are hosted/stored, allowing the recipient’s email app to download and display them on opening your email.

If you’re using CodeTwo Email Signatures 365 and you want to add linked images to a signature, be sure to use the Online picture option in the signature template editor. Learn more

At the same time, be aware that linked images are not a perfect solution. By changing the images in your email signatures to linked (online) images, you will indeed resolve the issue with replies coming from the native Mail app for iOS. However, this will also impact all emails that are viewed on Outlook email apps, as linked images will be blocked and not displayed automatically (recipients may need to manually download them). This is likely to affect most of your recipients.

Learn more about the pros and cons of using embedded and linked images

Switch to Outlook for iOS

Since the problem is exclusive to Apple’s native Mail app, switching to Outlook for iOS should solve it completely. On the other hand, this solution might be problematic if the affected recipients are outside your organization and/or aren’t willing to switch to a different email app. So be sure to focus on the part you can control (which is your organization) and encourage users to switch to Outlook (both Outlook for iOS and Outlook for Mac are the recommended and highly rated alternatives to sync your Microsoft 365 mail on Apple devices, allowing you to enjoy the integration with Microsoft’s business email to the fullest).

Additionally, if your organization uses CodeTwo Email Signatures 365, you can enjoy even more benefits with Outlook apps in place. For example, signatures can be added to emails directly in Mac/iPhone/iPad as users type their emails. Learn more

See also:

• How to fix common image-related problems in signatures
• Troubleshooting problems with emails and email signatures on mobile devices