Related Products: Exclaimer Cloud - Signatures for Office 365 | Exclaimer Cloud - Signatures for G Suite
On a reply or forward mail, this has become attachments and/or appears to be removed from the email.
Some mail clients such as Apple Mail can cause Embedded Images to be stripped from the signature template and/or become attachments.
Unfortunately, this also applies to a signature or text elements that have been rendered as a bitmap. Whether you are using a Custom Font or a Background Image.
The only way to resolve this issue is to use a font stack in the signature template, this will allow you to use a custom font with fall back fonts next to it for the mail client to choose the next one available, in the list. Further information for this can be found here - 'Using custom fonts without rendering as bitmaps'
If you are using a background image, you may be able to substitute this as a banner image or use a background color and split the image into different parts, as a suitable workaround.