3CX DLL-Sideloading attack: What you need to know
For some time now, some emails that I have been sending from Outlook are bouncing.
At the moment an email arrives informing me of the following error:
554 5.7.1 Service unavailable; Sender address [firstname.lastname@example.org] blocked using uri.cal1.sophosxl.com
Does anyone know how it can be solved?
Hello Jorge Benítez,Thank you for reaching out to the community, would request you to submit a sample.
Thanks & Regards,_______________________________________________________________
Vivek Jagad | Team Lead, Global Support & Services
Sophos Community | Product Documentation | Sophos Techvids | SMSIf a post solves your question please use the 'Verify Answer' button.
Dear Vivek Jagad
A few days ago I sent an email to the address email@example.com but I have not received a response.
Could you help me please.
Hey Jorge Benítez, upon submitting the samples to Sophos Labs, you'll never receive a response, but based on your request i.e. false positive or false negative they'll rectify the reported issue in 4-5 business working days, I would request you to please check whether or not the issue still exist or not ?Additionally you can let me know the subject line , your email address and date when you submitted the sample to firstname.lastname@example.org
Hi Vivek Jagad
The email was sent on Friday, October 21 with the subject "Submit a sample" and the email from which it was sent is "email@example.com"
I appreciate your kind help friend.
Jorge Benítez Greetings! I have checked our lab's not-spam queue and found that the sample was malformed. Please make sure that the steps within the KB article https://support.sophos.com/support/s/article/KB-000033422?language=en_US is followed and try sending again. I will see if anything can still be done from the current received email sample and will update you either from a new case or here. ALSO, please make sure that what you send us is the original email that was blocked/stopped by the product. This should be in the "Sent" folder of the sender account.
Jorge Benítez I spoke with our labs and it looks like the affected domain/URL was categorized as spam source before - probably due to a previous issue. Anyway, this detection has now been corrected. Please try sending a new email and let us know if the issue persists or not. Thanks!
Hi josepalad and Vivek Jagad , I appreciate your great help, we can now send messages to the domains where the emails bounced. Greetings friends