Dear Zoho Campaigns Users,
Some of you faced a massive delivery problem with Gmail recently. Around 25% of the campaigns that were sent to Gmail mailboxes between 20 June 2021, 23:00 PDT and 21 June 2021, 22:15 PDT were bounced. We also observed that emails sent to other mailbox providers did not have any issues.
Here’s the error message the campaigns, sent to Gmail, got bounced with:
Upon analysing, we found that one of the Zoho Campaigns users had sent malware content to their mailing lists. This made the Gmail system to not just block this particular user's campaigns but also genuine campaigns from other users. We have tried to contact the Gmail team to resolve this issue and we are yet to hear from them.
However, we started to debug the issue by trying to identify the pattern in which Gmail blocks our campaigns, and after a while we’ve successfully bypassed their block. We figured that the Gmail system blocks emails by matching a portion of our click URL string and we’ve fixed it now by changing the pattern of the click URL. We also identified the malicious user and blocked them.
The campaigns bounce issue with Gmail has been resolved now!
Our team is constantly working to streamline our antispam and malware systems to detect any such malicious content and eliminate them. In future, we will also be validating the HTML and downloadable content of the URLs present in the email campaigns to detect any fraudulent activity.
We sincerely regret the inconvenience caused. We will make sure such instances don’t recur in your email marketing experience with Zoho Campaigns in future.
Thanks and Regards,
Manager - Email Deliverability,