Sergii Zagryvyi

@chuuuan, thanks for raising this issue! Sorry for the late reply. Is this problem still present? Does it work if you hit the API from the postman with the same...

@Kristianrosland, thank you for raising this issue. Yes, the total email message size must not exceed 15MB. https://dev.mailjet.com/email/reference/send-emails/#:~:text=The%20total%20size%20of%20attachments,should%20not%20exceed%2015%20MB. https://documentation.mailjet.com/hc/en-us/articles/360043179773-What-is-the-size-limit-for-attachments-files-sent-via-Mailjet When I've tried to use the latest okhttp-client 5.0.0-alpha.10, the error...

@stefanbethke , thanks for raising this issue! Sorry for the late reply. All dependencies have been updated to the latest in the 5.2.1 release. Does it resolve the issue?