Inserting Multiple Images in Email Composer - Airmail for macOS

Some Airmail users on macOS encounter difficulties when trying to attach or embed several images within the same email message. Behaviours commonly reported include: only the first selected image being inserted, large images being heavily compressed, the composer becoming unresponsive after dragging multiple files at once, or recipients receiving a message with no visible images while attachments appear correctly on the sender side. This article outlines the recommended workflow and the most effective troubleshooting steps to ensure that messages with several images are sent reliably and displayed correctly on the recipient's end.

Recommended workflow for attaching multiple images

When you need to add several images to a single email, please use the following procedure rather than dragging the entire selection in one action:

1. Open Airmail and click the Compose button to start a new message.
2. 2. Position the cursor inside the body of the email at the point where you want the images to appear.
3. 3. Click the paperclip (attach) icon in the composer toolbar, or use the keyboard shortcut Command + Shift + A, and select your images one folder at a time. Inserting images in groups of three to five tends to be the most stable approach, especially when each file exceeds 2 MB.
4. 4. Wait for each image to be fully uploaded and previewed in the body of the message before inserting the next batch. The progress indicator at the bottom of the composer will confirm when the upload has completed.
5. 5. After all images have been added, review the layout and, if necessary, drag the thumbnails to reorder them.

Sending images as inline content versus as attachments

Airmail allows you to send images either inline (embedded directly within the message body) or as separate attachments. If recipients report that images are missing from your messages, the most frequent cause is a difference between how the inline content was generated on macOS and how the receiving mail client renders HTML emails. As a workaround, we recommend sending the same message twice in a controlled way: once with the images embedded inline and once with the same files attached at the bottom of the message. This makes the content accessible regardless of the recipient's mail application.

Reducing image size before sending

When messages contain several high-resolution images, the total size can easily exceed the limit imposed by the outgoing SMTP server (typically 25 MB for most providers). Should the message fail to send, please consider the following:

• Resize the images using the Preview application on macOS (Tools > Adjust Size) before attaching them, targeting a maximum width of 1600 pixels for general-purpose photographs.
• - Export images from Photos using the Small or Medium preset rather than Original.
• - For very large sets, use a cloud-sharing link (iCloud Drive, Dropbox, Google Drive) and paste the link inside the message body, instead of attaching every file directly.

Troubleshooting steps

If, after following the recommendations above, the issue persists, please try the following diagnostic steps in order:

1. Quit Airmail completely (Command + Q) and relaunch it. Some image-handling issues are caused by a single composer window losing reference to the upload queue, and a clean restart resolves them.
2. 2. Check the available disk space on the volume where the Airmail cache is stored. A nearly full disk frequently causes silent failures during image processing.
3. 3. Open Airmail Preferences > Composer and confirm that the option for inline images is enabled if you intend to send embedded images, or disabled if you prefer plain attachments only.
4. 4. Try sending the same message to a second test address (for example a Gmail account you control) to determine whether the issue is reproducible across different recipients or specific to one mail server.
5. 5. If the recipients use Microsoft Outlook, ask them whether they see a small placeholder icon instead of the image. In that case, please ask them to right-click the message and choose the option to download external images, as Outlook frequently blocks remote content by default.

When to contact support

Should the problem persist after performing the steps above, please open a new conversation with our support team and include the following information so that we can investigate efficiently:

• The exact version of Airmail (visible under Airmail > About Airmail).
• - The macOS version (Apple menu > About This Mac).
• - A short description of the issue (for example: only the first image is inserted, the composer freezes, recipients see no images).
• - One example of an email that triggered the problem, ideally forwarded to our support address with the original attachments preserved.

Our technical team will analyse the case and provide a tailored recommendation as soon as possible. We sincerely thank you for your patience and for helping us continuously improve Airmail.

Updated on: 05/08/2026