Do you happen to have greylisting turned on?  From what server are these emails originating?  It is possible that the incoming messages are being greylisted and thus delayed until their server re-attempts.  You can check the SMTP for "451 Greylisted, please try again in xx seconds" for any related messages.

In addition to Robert's response, another thing that can cause delays on incoming emails are delays when communicating with RBL/URIBL list servers from your SmarterMail server. To check that you can log on as a system administrator, then navigate to Settings>Antispam>RBLs/URIBLs and check for any of those entries showing a high response time. Generally, anything over 5000Ms is problematic and will lead to delays on delivery/spam checks. 

To correct those you'll want to investigate what might be delaying your connectivity to those lists. For the near term though, you can disable any lists that are showing extreme delays to get email flowing a little quicker/smoother while you get to the bottom of those delays. Hope that helps as well!

Darren, 

To add to what Robert and Kyle said, if you know what domain any emails are coming from you can add them to your domain or user trusted senders list. Any email addresses or domains on the trusted senders list will bypass greylisting. This can be found in either Domain Settings or User Settings under Spam Filtering. You should see a Trusted Senders card.

Appreciate all the responses so far! Will try the suggestions offered. Thank you!

Hello,

Thanks again for your suggestions!

Our web address to reach our login is mail.firstkingsville.org. I typed in the user and password for username root and logged in successfully (root is listed as Primary Administrator in the Accounts tab).  However, when I click on both Settings and Domain Settings buttons at the top, I cannot find any SMTP logs (using Domain Reports button or otherwise) that would show the 451 message, and there is no Antispam option in the navigation pane - just "Spam Filtering" - and I could not otherwise locate the RBLs/URIBLs.  Also, I was able to see the domain reports for greylisting, and they show that it is operational for us and delays nearly half our emails.  I was able to find the Trusted Senders card under Spam Filtering.

Am I not actually logging in as admin?  Any thoughts on what step(s) I'm missing?  Below is a screen cap of my screen while logged in as root and with the Accounts tab showing, indicating root as Primary Administrator.

Thanks!
Daren

@Daren - it looks like you're logging in with a domain administrator account rather than a system administrator account. System administrators lack the @domain.com portion of their username. If you are logging in with just root it's possible something else might be happening here. In that case, do you use Active Directory/LDAP authentication with this domain? If so, the attempt to log on with root is likely being hooked by the AD authentication and logging you in to the domain instead. You should be able to access the web interface from the server on the http://localhost:9998 interface and log in that way, as it uses the domain name to associate the domain. I hope this helps! :)

@Kyle - thanks for the assessment of our issue.  It led me to discover that we have our Smartermail setup through a 3rd party (Faithconnector, which also hosts our website), and it looks like they would be the ones who are able to log in as system admin (or would know the web address to go to in order to do so).  The regular webmail login is mail.firstkingsville.org which turns into https://webmail1.nextmeta.com/interface/root#/login but I couldn't figure out anything more about if we even have access to log in as system admin.  I did try the link you suggested, but our use of Faithconnector means we don't host the mail server in-house - at least, I'm guessing this is why the localhost:9998 option doesn't seem to work. I did go ahead and submit a help request to Faithconnector.  Any additional thoughts are appreciated, but if it sounds like I need to resolve this through Faithconnector, just wanted to say thanks again for your help and the others' help on this forum!  You've helped me understand the issue and lead me in the right direction.  God bless, Daren  

You're very welcome Daren! Always happy to lend a hand, and you'll find the users on this community are an amazing source of information and guidance. Your findings would mean your SmarterMail instance is being hosted for you, and in that case you won't have system administrator access. I recommend reaching out to NextMeta to see what they can tell you about the logging associated with this issue and that way they can reach out on a support ticket if they need help getting to the bottom of it. Have a good one!

Thanks! I contacted NextMeta and they confirmed that greylisting is on for all their clients and cannot be turned off.  My followup question for this forum is, can the delay produced by greylisting be decreased?  Or does the delay depend on how the greylisted domain responds to being greylisted?

Thanks again,

Daren

@Daren, the greylist block period is configurable at the system admin level.  You will need to follow-up with NextMeta about adjusting that.  It is a server-wide setting though.  If they allow users to override the greylisting, then you could turn off greylisting for some or all of your domain users.