Mailgun Deliverability Issues - mailgun

I'm going to be migrating a lot of customers off Mandrill soon and Mailgun sounded pretty good so I moved one small client over but already have a bounce to a valid address:
Server response: 554 554 BigPond Inbound Connection refused. IB112
This looks to me like the customer's email host / ISP is refusing to accept messages from a Mailgun IP.
This is very worrying as one of their competitors has also claimed they worst deliverability of the big players in this space.
Any past and present Mailgun users have issues such as this? (This was very very rare with mandrill). Would hate to migrate 20+ customers to a platform that has really bad deliverability as these are ecommerce related emails so very important that they are delivered.

After experiencing further delivery issues I contacted them and they apparently "moved me to a different node". Still experienced delivery issues.
Ended up moving to postmark and it's been flawless. Highly recommend postmark if you are sending transactional emails only and no bulk mail.

Related

call to external API is getting blocked on Google cloud compute engine

I am trying to connect to an external API from .net.
It is working as expected from other machines.
But we are not getting any respond from the API call when trying from the server.
We have tried accessing the api url on the browser and it failed with the same no response error.
This is what we have done so far.
We have checked VPC firewall and tried some firewall rules ( Google Cloud firewall) and made sure that there is no blocking to this API.
We have checked Windows firewall and it is switched off now. We also made sure that there is no rules to block this API. However to test it further, we are now switched it off.
Checked that we are able to connect to other websites from the server.
Checked whether we can access the API from other machines. We are able to connect to the API successfully using the tokens from the server.
We have also installed Wireshark to analyze the incoming and outgoing packets from the server. From this analysis, we were able to find that there are network packets sending to this API and it is trying the retransmits the packets, but there is no acknowledgement packet received. This might be of the below two scenarios.
The acknowledgement packet sent from the API server lost in transition.
The data that we have sent from the server to the API lost in transition.
Contacted the API technical team and made sure that the IP is not getting blocked on their end.
Tried contacting Google Support but we have not received much help from them as ours are in "Bronze plan"
This was working without any issues from the server in the past. Not sure what is happening now.
Thank you in advance for all the helps.
Thank you Jeffrey and Patrick for your kind reply. As suggested by Patrick, I am adding here my comments as an answer to close this post. We were able to identify the issue from the wireshark analysis. It was the API provider who was blocking the IP. We have contacted them again with the results and they confirmed this. Thank you very much.

Magento 2.0 hosted on Google Cloud - Email/Smtp Issue

I have no computer knowledge, so here under a message from my developer to you :
"All the email related problems are occurring because the server is not able to fire mail.
The smtp details you provided are ok and are working at our server well. But when we try to fire a mail using the given smtp details on your server it shows an error.This is the testing url for smtp mail http://kzdiffusion.fr/smtpmailertest/testemail.php
Please ask the hosting provider to resolve the issue.
After that we will create an extension to send mail through smtp"
Can you please help with that problem above, please ?
My project is already delayed 2 months. Every tips that can help moving forward is a big plus. Google Support is not answering my emails anymore.
Best Regards,
David.
GCP blocks standard email ports , you can choose a non-standard port to send email through. You can also take advantage of the mail services offered by Compute Engine partners: SendGrid, Mailgun, and Mailjet.
See here: https://cloud.google.com/compute/docs/tutorials/sending-mail

Can I restrict cfmail to only send mail from a given domain using cf admin

We have had issues with our server being used to send spam via cfmail to our remote SMTP server. I cannot see where it is occurring, but the emails are sent from a domain that is not one on our server.
Is there a way using ColdFusion administrator to specify that only emails showing as from someone#mydomain.com are sent to the SMTP host via the spool?
Thanks in advance,
Paul
It sounds to me like the <cfmail> side of things here is a red herring and you have got an open relay on your mail server. You seriously need to disable that immediately! If your SMTP server has to relay email for your CFML app then make sure it's not configured to relay everything, instead just for the IP address of the CF server, or for the credentials the CF server uses to connect to it.
If you don't know how to configure the relaying settings for your SMTP server, raise another question on serverfault.com asking how. Provide the exact details of your SMTP server, as well as the requirement to still allow relaying for the CF server.

Coldfusion 9 cfexchangecalendar exchange server outlook 2007

CF9
Exchange server 2007 (hosted)
I am trying to add a calendar event for a user on our hosted exchange server. I'm getting the error ;
Unable to connect to the Exchange server using HTTP/HTTPS protocol.
HTTP response code : 400
The code is;
<cfexchangeCalendar action="Create"
username="EXCH016\ron_domain"
password="password"
mailboxname="ron"
server="https://owa016.msoutlookonline.net/owa"
Protocol="https"
formbasedauthentication=true
formbasedauthenticationURL="https://owa016.msoutlookonline.net/owa/auth/owaauth.dll"
Event="#sEvent#"
result="theUID">
#theUID#<br>
I know I can contact the server using the following;
<cfhttp URL='https://owa016.msoutlookonline.net/owa' result='res' >
<cfdump var="#res#">
<cfoutput>#res.filecontent#</cfoutput>
I get the form that requests email address and password.
I've been working on this problem for some time now. I can go to the owa page via browser and log in. At this point I'm at a loss on how to debug the problem.
I have had the same type of problem in the past, when one of my customers went from Privately Hosted and Run vs Hosted Solutions.
Although, I never used the formbasedauthentication method when authenticating, maybe this bypasses some of my issues.
The big thing we had issues with is that most Providers don't all WebDav access on their servers.
Since you are getting a 400, bad request, this is what I would look for first.
http://livedocs.adobe.com/coldfusion/8/htmldocs/help.html?content=cfexchange_3.html talks about what CF needs to connect to Exchange, maybe see if the support staff can confirm the setup.
Since you are using HTTPS, have you added the Cert into the JRE cert Store?
Sorry this probably isn't much help, but I hope it helps.

Sending emails without using SMTP Server

I want that my program could send email without using Microsoft Outlook or other programs or SMTP server. Is that possible? Can I send email without connecting to SMTP server?
You can't by definition, since email gets through the recipient at least passing through the SMTP server of his/her domain.
You may send it directly to the recipient's SMTP server instead of going through the ISP's server getting its data through DNS (which is basically re-implementing a local SMTP server on your own), but it's not a good idea, since many target servers will refuse to accept your mails due to spam concerns (your connection will probably come through graylisted "residential" IP addresses, it won't have a rDNS record, ...).