About this article
This article details technical questions and answers regarding the Templafy Email Signature Server. Sections in this article:
- What is the Templafy Email Signature Server architecture?
- Does the Email Signature Server work with third-party email processing services?
- Is the Email Signature Server disrupted by antivirus software on Desktop PCs?
- Does the Email signature server update cause any downtime?
- What happens to an e-mail if there is an error during processing
- Does Templafy Email Signature Server support plain text format emails?
- Does the Email Signature Server work with encrypted emails?
- How does the Email Signature Server impact or work in conjunction with connectors used to encrypt traffic for customers' customers?
- How Templafy Email signature server integrates with Exchange using EWS?
- What if emails are not being sent?
What is the Templafy Email Signature Server architecture?
Templafy relies on a Kubernetes architecture, and the native cloud service of Microsoft Azure Kubernetes service also known as AKS for the Email Signature Server.
AKS allows for having orchestration layers on the server, load balancing emails between the servers, and offers a highly available environment.
Templafy Email Signature Server solution supports the cluster auto-scaler in AKS to create automatically additional servers in the event of a high load.
Does the Email Signature Server work with third-party email processing services?
Customers may already have configured third-party email processing services performing virus scans or other services related to email processing in their email flow (e.g., Mimecast, Proofpoint, Sophos, Barracuda). To avoid any conflict and ensure deliverance of signatures, Templafy recommends setting the Templafy Email Signature Server mail flow rule to Priority 0, which means the first service to process the email.
Is the Email Signature Server disrupted by antivirus software on Desktop PCs?
Certain antivirus software add their own signatures to the emails they have processed (e.g., "This email was verified by ..."). The Email Signature Server is not affected by these as the signature is always appended at the end of the email after it has been sent.
Does the Email signature server update cause any downtime?
Templafy Email signature server updates are done on a hot system, meaning it can be done without causing any downtime since Kubernetes will orchestrate it internally.
What happens to an e-mail if there is an error during processing or an Email Signature Server pod crashes?
For every single email sent to Templafy Email Signature Server Exchange Online will keep a copy inside the Exchange Online queue until it returns after being processed for an email signature.
If there is a signal back to Exchange Online that there was an issue with processing the e-mail to attach a signature, or if the Email Signature Server pod processing the e-mail crashes, then the original unprocessed e-mail held in the Exchange Online queue will be sent on to the final recipient.
Does Templafy Email Signature Server support plain text format emails?
Templafy Email Signature Server only applies HTML signatures. If the emails are plain text format, they will be converted to HTML in order to have the signature applied.
Does the Email Signature Server work with encrypted emails?
If the messages are encrypted before they reach the Email Signature Server, the emails will not be processed by the Email Signature Server and will be sent on to the final recipient without a signature being appended by the Email Signature Server.
If the email is encrypted by a mail flow rule rule configured in Exchange Online Admin Center, and Templafy Email Signature Server is the first mail flow rule (set to Priority 0), the email signature will be attached before the email is encrypted by a subsequent mail flow rule processing.
How does the Email Signature Server impact or work in conjunction with connectors used to encrypt traffic for customers' customers?
If the Templafy mail flow rule that sends emails to the Email Signature Server is in line before the rules that do any further processing of emails, e.g., encryption, the Email Signature Server applies a signature as expected.
How Templafy Email signature server integrates with Exchange using EWS?
Templafy integrates with Exchange using EWS (Exchange Web Sockets) through an Azure AD Enterprise application to allow Templafy ESS updating the sent items and converting any TNEF/RTF e-mails into HTML.
The communication is entirely secure relying on an SSL certificate generated by the client. This application also requires Application permissions
full_access_as_appto be able to accomplish these updates.
What if emails are not being sent?
The Email Signature Server is optimized for high load. If incidents occur and the connection to the Email Signature Server is not available or the server is unable to process requests, emails will defer in the Exchange Online queue. Exchange Online retries sending these queued emails starting at 15 minutes, for up to 24 hours. The emails will be sent as soon as the service is restored to the Email Signature Server, alternatively the sender will receive a Non-Delivery Receipt after 24 hours.
You are encouraged to review the Microsoft Service Health for any reported incidents for your subscription that involve Exchange Online. These incidents may involve impact to mail flow and delivery not necessarily related to the Templafy Email Signature Server.
- Check the message trace for one of the e-mails in the Microsoft 365 Exchange Admin Center
- Check that the connectors in the Exchange Admin Center are still valid and active
- Check the Resource Health for the Email Signature Server AKS cluster in the Azure Portal
- Bypass the Email Signature Server by disabling the mail flow rule in the Exchange Admin Center