Tags: D365FO, Emailing, Exchange, Free Edition, Images, SMTP 
How to use images in outgoing emails
In general, there are 3 ways to embed images in your emails:
- Inline embedded CID images
- Inline embedded Base64 encoded images
- Linked images (specified via URLs)
Embed an image using CID (Content-ID) in the HTML email body, while attaching it to mail message (as Linked Resource).
Pros: Does not depend on external sources.
Cons: Has to be done programmatically and increases the email size.
Embed an image directly in the HTML email body as the Base64 encoded string.
Pros: Does not depend on external sources.
Cons: Has to be done programmatically, might be blocked in some email clients (ex. Gmail web client) and increases the email size. Email body source becomes quite unreadable.
Embed an image using its full URL path in the HTML email body; the image needs to be stored on a public cloud storage.
Pros: Minimal email size.
Cons: Might be blocked in some email clients and requires download from external servers.
Are images supported in the email body of outgoing emails in D365FO
When it comes to emailing reports in D365FO, there is no support for the email body OOTB, so we can't really talk what's supported and what's not 😀.
On the other hand, for outgoing emails based on Organization and System email templates sent out from D365FO using Email processing (Batch email sending status and Email distributor batch), you can edit the email body and use static Linked images OOTB.
If you decide to customize your code and support email messages with CID or Base64 encoded images, note that Docentric versions before 3.4.8.4 have a problem with CID images when emails are sent with D365FO Exchange or Graph email providers. Older versions embed CID images as linked resources on alternate view which is not supported by these email providers. Since version 3.4.8.4 CID images are embeded as (hidden) inline attachments which works fine with all email providers and email clients.
Use email images in Docentric
Docentric Free Edition enables emailing reports with the email body, supporting all 3 types of embedded images (CID, Base64 and Linked images). Additionally, you can use Email processing for emailing reports or preconfigured Report Email templates. Also, you can use Email templates improved by Docentric to design Alert and Workflow notifications, using the same Email body editor that supports all 3 types of embedded images.
This is how Docentric Email body editor looks.
Optional: Convert CID to Base64 encoded images
If you are using Docentric version older than 3.4.8.4 and you want to use Exchange or Graph email provider (to avoid additional mail server configuration for Office 365 SMTP Relay or because of deprecation of SMTP with Basic authentication), you can use the following extension to convert all CID images in your outgoing emails to Base64 encoded images.
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/// <summary> /// The class SysMailerExchange_WE_Extension is an extension of the class SysMailerExchange. /// </summary> [ExtensionOf(classStr(SysMailerExchange))] final class SysMailerExchange_WE_Extension { /// <summary> /// Sends the message to the Exchange server, logging appropriate telemetry and inserting history records. /// </summary> /// <param name = "_message">The message to be sent.</param> /// <param name = "_interactive">Indicates if the message was created interactively.</param> /// <param name = "_correlationId">The ID that correlates the related telemetry.</param> /// <returns>True if the message was successfully sent, else false.</returns> protected boolean sendMessage(System.Net.Mail.MailMessage _message, boolean _interactive, guid _correlationId) { if (_message != null) { // Replace CID embedded images with Base64 embedded images in the provided email message. DocEmailMngHelper::replaceCIDWithBase64EmbeddedImages(_message); } return next sendMessage(_message, _interactive, _correlationId); } } |
This is an optional extension, and you are free to use it!
Of course, there is a method in our Docentric Free Edition library DocEmailMngHelper::replaceCIDWithBase64EmbeddedImages(), so you are welcome to install it.
If you are not eager to do so, check the source method below 😀
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/// <summary> /// Replaces embedded CID images with Base64 encoded images in the provided email message. /// </summary> /// <param name = "_mailMessage">Email message</param> public static void replaceCIDWithBase64EmbeddedImages(System.Net.Mail.MailMessage _mailMessage) { if (_mailMessage == null) { return; } // Replace CID embedded images with Base64 embedded images AlternateViewCollection alternateViews = _mailMessage.AlternateViews; for (int i = 0; i < alternateViews.Count; i++) { AlternateView alternateView = alternateViews.get_Item(i); if (alternateView.ContentType.MediaType != 'text/html') { continue; } LinkedResourceCollection linkedResources = alternateView.LinkedResources; for (int j = 0; j < linkedResources.Count; j++) { LinkedResource linkedResource = linkedResources.get_Item(j); if (linkedResource.ContentId == null || linkedResource.ContentStream == null || (!(linkedResource.ContentStream is MemoryStream)) || linkedResource.ContentType.MediaType == null || !linkedResource.ContentType.MediaType.StartsWith('image/', System.StringComparison::OrdinalIgnoreCase)) { continue; } str cidString = System.String::Format('cid:{0}', linkedResource.ContentId); str base64Image = DocGlobalHelper::convertToBase64String((linkedResource.ContentStream as MemoryStream).ToArray()); str dataString = System.String::Format('data:{0};base64,{1}', linkedResource.ContentType.MediaType, base64Image); _mailMessage.Body = _mailMessage.Body.Replace(cidString, dataString); // Delete CID attachment linkedResources.RemoveAt(j); j--; } } } |
See also
Email reports with images from database in the email body in D365FO >>
Troubleshooting techniques for solving emailing issues in D365FO >>
Batch email sending status improvements >>
Email or print an invoice from D365FO, depending on the customer’s email address availability >>
Emailing related articles >>