Our underlying SMTP vendor, Sparkpost, has reported an intermittent issue with email deliverability that might cause some delays in dispatching mails via Sitecore EXM and Email Cloud solutions.
Please see additional details: https://status.sparkpost.com/incidents/y445hs9ql5dc
Resolved: The Email Cloud vendor completed their observations of the implemented fix and have marked this issue as resolved.
Update: The Email Cloud Vendor, SparkPost, implemented a fix for this issue, and are monitoring the results.
Identified: An intermittent issue was identified by the Email Cloud vendor.