Synology Mailplus not recieving emails Synology Mailplus not rec...

Topic: Synology Mailplus not recieving emails

Post Synology Mailplus not recieving emails
by flowmoldcasting on samedi 10 octobre 2020

My Synology Mailplus is not receiving any emails including emails send to myself. It does send emails fine to gmail.
I am using both Dynu inbound and outbound relay service with my Synology NAS hosted at home. The ISP is comcast blocking port 25. I am using my own domain managed by google. Had DDNS setup for both my domain.com and mail.domain.com. Dynu does see the email sent to the domain.com but synology does not see it. I disabled authentication, DKIM, SPF and DMARC. Cannot figure out why. Hope someone can help here.

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Post Re: Synology Mailplus not recieving emails
by flowmoldcasting on samedi 10 octobre 2020

Edit: I do can get emails sent to myself. took some time but it did show up eventually.

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Post Re: Re: Synology Mailplus not recieving emails
by blainec on dimanche 25 octobre 2020

frankzz8000 wrote:Edit: I do can get emails sent to myself. took some time but it did show up eventually.
did you ever get this working?
I'm having a problem with recieving emails as well

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Post Re: Synology Mailplus not recieving emails
by SgBodzin on lundi 21 décembre 2020

I am having the same problem with Synology MailPlus Server not delivering email to MailPlus client. Using Dynu email store/forward. All MX Tools and Dynu tools show successful messages for each of the tests. I can send emails to myself from MailPlus via MailPlus Server. Outgoing SMTP works perfect. Using ComCast with port 25 blocked caused me to setup Dynu with forwarding to 2525 as recommended. Cannot receive any emails from external sources. All required router ports open for email like 2525.

Did you get the problem solved?
Stewart

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Post Re: Re: Synology Mailplus not recieving emails
by DNYUfd521fC on lundi 8 février 2021

Same problem here. A few days ago the e-mails arrived after about 10 minutes. This week they do not come at all. I'm using comcast (xfinity) internet service. The outbound e-mails were delivered in a few seconds. I tried enabling DNS server on my synology as well and that did not help. I would love to hear if anyone was able to figure out how to get it to work.

SgBodzin wrote:I am having the same problem with Synology MailPlus Server not delivering email to MailPlus client. Using Dynu email store/forward. All MX Tools and Dynu tools show successful messages for each of the tests. I can send emails to myself from MailPlus via MailPlus Server. Outgoing SMTP works perfect. Using ComCast with port 25 blocked caused me to setup Dynu with forwarding to 2525 as recommended. Cannot receive any emails from external sources. All required router ports open for email like 2525.

Did you get the problem solved?
Stewart

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Post Re: Synology Mailplus not recieving emails
by vesey on lundi 8 février 2021

One thing to try is to use STARTTLS instead of SSL/TLS as Connection Security in the Dynu control panel and do not enable SMTP authentication.


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Post Re: Synology Mailplus not recieving emails
by everyonedesigns on samedi 23 octobre 2021

i also have the same set up and have the exact same problems.

Has anyone gotten this resolved?

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Post Re: Synology Mailplus not recieving emails
by sdmf on lundi 1 novembre 2021

I have same problem on receiving email.

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Post Re: Synology Mailplus not recieving emails
by dougblair on jeudi 4 novembre 2021

I have a very similar setup - Synology MailPlus Server on my home network and Apple mail clients connect to it OK. I also have just set up Dynu for email store and forward and for outbound relaying. The fact that your emails do show up *eventually* sounds like the Dynu servers might not be whitelisted and so are going through the MailPlus server GREYLIST delay. When delayed by GREYLISTING MailPlus will tell Dynu that it's a temporary failure and try again later, and Dynu will try again and the greyloist timeout might not have completed, so it try again even later.

To fix this go to the MailPlus app on your Synology server (mine is a DS1817+) and navigate to Security -> Spam, -> Greylist settings, and add an entry for each of the IP addresses used by Dynu. There are 6 lines - 5 network ranges and one specific address.

If it's not greylistsing you might want to check the queue on Dynu -> Email Services -> your domain -> Store and Forward -> Queue and see if the emails are waiting there. I haven't yet explored what you can do to get them moving, this is only day one for me here.

Doug

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Post Re: Synology Mailplus not recieving emails
by flowing on dimanche 16 janvier 2022

Guys, I'm in the same boat question here:

What do you use for the main server while using Outlook? If I'm inside my home I can use the IP for the synology and it gets mail. When I'm outside the home. I tried my domain, DDNS and nothing.

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Post Re: Synology Mailplus not recieving emails
by MAHV on mardi 25 janvier 2022

Same here using Synology email server.
Yesterday I could send an receive test-emails using Dynu control panel. Today I do not receive any test emails, although Dynu tells me the queue is empty and according to the Notes-section the emails are send to Synology email account. To keep it simple, I've disabled secure connection for now (now wise, I know).

Emails send from a gmail account to Synology email (via Dynu) do not arrive at all, MX-records are set according to manual.

Dynu is not blacklisted and looks like a black-hole to me for now.

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Post Re: Re: Synology Mailplus not recieving emails
by MAHV on mardi 25 janvier 2022

dougblair wrote:I have a very similar setup - Synology MailPlus Server on my home network and Apple mail clients connect to it OK. I also have just set up Dynu for email store and forward and for outbound relaying. The fact that your emails do show up *eventually* sounds like the Dynu servers might not be whitelisted and so are going through the MailPlus server GREYLIST delay. When delayed by GREYLISTING MailPlus will tell Dynu that it's a temporary failure and try again later, and Dynu will try again and the greyloist timeout might not have completed, so it try again even later.

To fix this go to the MailPlus app on your Synology server (mine is a DS1817+) and navigate to Security -> Spam, -> Greylist settings, and add an entry for each of the IP addresses used by Dynu. There are 6 lines - 5 network ranges and one specific address.

If it's not greylistsing you might want to check the queue on Dynu -> Email Services -> your domain -> Store and Forward -> Queue and see if the emails are waiting there. I haven't yet explored what you can do to get them moving, this is only day one for me here.

Doug
Hi Doug,

Can you please let me know the "IP addresses used by Dynu".

Thanks!

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Post Re: Re: Re: Synology Mailplus not recieving emails
by dougblair on mardi 25 janvier 2022

Hi

The IP addresses may change from time to time, but should always be listed in the Dynu FAQ pages.

Look here:

https://www.dynu.com/FAQ/Email-Service#EmailStoreForward

Doug

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Post Re: Synology Mailplus not recieving emails
by boldin on jeudi 26 mai 2022

Did you ever get this working? I appear to be having the exact same issue.

I can send emails successfully on my Synology MailPlus server to outside domains and to inside my domain.

I cannot send emails successfully on my outside domain email addresses (e.g. gmail, etc.) to my Synology MailPlus server.

I see that the mails are queued in my store/forward service but are not making it to my system at home. I have verified that port forwarding is correct and the ETRN test is successful.

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Post Re: Synology Mailplus not recieving emails
by nova168168 on mardi 26 juillet 2022

you must use the port 2525 for the smtp !

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mardi 19 mars 2024 02:22
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