Need help?

Our experts have had an average response time of 12.14 minutes in September 2021 to fix urgent issues.

We will keep your servers stable, secure, and fast at all times for one fixed price.

Smartermail 601 error – Let us discuss Causes and Solutions

by | May 23, 2021

The Smartermail 601 error, mostly, is a generic error message.

As part of our Server Management Services, we assist our customers with several Smartermail queries.

Today, let us discuss what leads to this error and its solutions.


Smartermail 601 error

Recently, one of our customers came across a bounce-back message starting with, “Remote host said: 601 Attempted to send the message to the following ip’s:”

Though a generic error message, the exact reason for this error can be found from the lines that follow it.

For instance, a typical error message looks like this:

Could not deliver message to the following recipient(s):
Failed Recipient: [email protected]
Reason: Remote host said: 601 Attempted to send the message to the following
xxx.xx.xx.xx (recipient ip address)


Causes and Solution

Let us now discuss the causes as well as the solution to them.

  • IP blacklist

One of the common reasons can be our sending IP address blacklisted in any RBL. Generally, this happens in the case of shared hosting environments where multiple users share a common mailing IP address.

Thus the first step is to confirm if the IP address is on the blacklist or not. To do so, we can use online tools like mxtoolbox.

On the other hand, to fix the error immediately without waiting for the delisting, we need to set up a new Outgoing Gateway.

We can update this from, “Settings > Routing > Outgoing Gateways >New.

  • DNS records

At times this error occurs because of a lack of proper DNS records.

Usually, the mistake will be with the SPF record. We need to ensure to include that the Smartermail IP addresses with the SPF records.

In addition, we need to ensure that the PTR records are set up correctly.

For that, we can call our ISP and ask them to active PTR records on our IP and domain name. Once activated, we have to wait for 24 hours for the changes to propagate.

We can also try setting our DNS server addresses under Settings>General.

For temporary purposes, we can use the Google public DNS servers:

Google DNS 1:
Google DNS 2:
  • Network problems

The error is likely to occur due to network issues as well. The connection could have been interrupted in transit, or dropped, or timed out.

The best way to test this is to run a telnet command from the server to the IP addresses that are in the 601 error.

Smartermail 601 error

Once done, we enter an EHLO command and check the response. If we get something other than a 220 response when making the original connection or a similar reply to the EHLO command we need to further troubleshoot the issue.

A network package sniffer can help with this.

It can also happen when the sending IP address blocks at the receiver. So we may need to contact the receiver end and whitelist it.

[Need help with the resolution? We’d be happy to assist you]



In short, we saw how our Support Techs fix the Smartermail 601 error.


Never again lose customers to poor server speed! Let us help you.

Our server experts will monitor & maintain your server 24/7 so that it remains lightning fast and secure.


var google_conversion_label = "owonCMyG5nEQ0aD71QM";


Submit a Comment

Your email address will not be published. Required fields are marked *

Privacy Preference Center


Necessary cookies help make a website usable by enabling basic functions like page navigation and access to secure areas of the website. The website cannot function properly without these cookies.

PHPSESSID - Preserves user session state across page requests.

gdpr[consent_types] - Used to store user consents.

gdpr[allowed_cookies] - Used to store user allowed cookies.

PHPSESSID, gdpr[consent_types], gdpr[allowed_cookies]


Statistic cookies help website owners to understand how visitors interact with websites by collecting and reporting information anonymously.

_ga - Preserves user session state across page requests.

_gat - Used by Google Analytics to throttle request rate

_gid - Registers a unique ID that is used to generate statistical data on how you use the website.

smartlookCookie - Used to collect user device and location information of the site visitors to improve the websites User Experience.

_ga, _gat, _gid
_ga, _gat, _gid


Marketing cookies are used to track visitors across websites. The intention is to display ads that are relevant and engaging for the individual user and thereby more valuable for publishers and third party advertisers.

IDE - Used by Google DoubleClick to register and report the website user's actions after viewing or clicking one of the advertiser's ads with the purpose of measuring the efficacy of an ad and to present targeted ads to the user.

test_cookie - Used to check if the user's browser supports cookies.

1P_JAR - Google cookie. These cookies are used to collect website statistics and track conversion rates.

NID - Registers a unique ID that identifies a returning user's device. The ID is used for serving ads that are most relevant to the user.

DV - Google ad personalisation

IDE, test_cookie, 1P_JAR, NID, DV, NID
IDE, test_cookie


These are essential site cookies, used by the google reCAPTCHA. These cookies use an unique identifier to verify if a visitor is human or a bot.