Cannot Send Batch Email

self-hosted, mailgun, node.js 16.5, mysql 8

I set up mailgun and entered domain, api credential into admin dashboard; also added smtp info to config.production.json

Users can receive secure sign in link via email, but new posts do not email, received error output below:

NAME: EmailError
CODE: BULK_EMAIL_SEND_FAILED
MESSAGE: The server encountered an error whilst sending email.

level: normal

“The email service was unable to send an email batch.”
EmailError: The server encountered an error whilst sending email.
at /var/www/html/versions/5.2.1/core/server/services/bulk-email/bulk-email-processor.js:249:30
at runMicrotasks ()
at processTicksAndRejections (node:internal/process/task_queues:96:5)
at async Object.processEmailBatch (/var/www/html/versions/5.2.1/core/server/services/bulk-email/bulk-email-processor.js:174:34)
at async Promise.map.concurrency (/var/www/html/versions/5.2.1/core/server/services/bulk-email/bulk-email-processor.js:102:17)

[2022-06-03 02:30:22] INFO “GET /ghost/api/admin/posts/6299722a0cbb9b0166c5ee48/” 200 51ms

Same issue on my side since I change my hosting …
I also use Mailgun.

{"name":"Log","hostname":"sd-130779","pid":188628,"level":40,"err":{"id":"a0a5fb80-346f-11ed-9df9-8f65f3114eb6","domain":"xxxx","code":"BULK_EMAIL_SEND_FAILED","name":"EmailError","statusCode":500,"level":"normal","message":"The server encountered an error whilst sending email.","context":"\"The email service was unable to send an email batch.\"","stack":"EmailError: The server encountered an error whilst sending email.\n    at Object.send (/data/www/xxxxx/versions/5.14.1/core/server/services/bulk-email/bulk-email-processor.js:259:30)\n    at runMicrotasks (<anonymous>)\n    at processTicksAndRejections (node:internal/process/task_queues:96:5)\n    at async Object.processEmailBatch (/data/www/xxxx/versions/5.14.1/core/server/services/bulk-email/bulk-email-processor.js:182:34)\n    at async Promise.map.concurrency (/data/www/xxxx/versions/5.14.1/core/server/services/bulk-email/bulk-email-processor.js:105:17)","hideStack":false},"msg":"The server encountered an error whilst sending email.","time":"2022-09-14T20:55:55.962Z","v":0}
Error: Worker for job \"email-analytics-fetch-latest\" exited with code 1\n  

I’m getting this error as well. Any help would be appreciated.

The server encountered an error whilst sending email.
"The email service was unable to send an email batch."
Error ID:
Error Code: 
    b0d16870-38a0-11ed-bfdf-2feb196daab5
    BULK_EMAIL_SEND_FAILED
----------------------------------------
EmailError: The server encountered an error whilst sending email.
    at Object.send (/var/lib/ghost/versions/5.14.1/core/server/services/bulk-email/bulk-email-processor.js:259:30)
    at runMicrotasks (<anonymous>)
    at processTicksAndRejections (node:internal/process/task_queues:96:5)
    at async Object.processEmailBatch (/var/lib/ghost/versions/5.14.1/core/server/services/bulk-email/bulk-email-processor.js:182:34)
    at async Promise.map.concurrency (/var/lib/ghost/versions/5.14.1/core/server/services/bulk-email/bulk-email-processor.js:105:17)