@amal Got a lengthy reply from sendgrid.
In short, it seems that my provider uses a general spam filter and sendgrid is currently blacklisted.
I’ll just use a different email address, but posting their
answer here for reference
I reviewed your account and it looks like an email sent to [email protected] was bounced with an error message “550 5.7.1 Access denied to 220.127.116.11 by zen.spamhaus.org DNSBL (The Spamhaus Project - ZEN)” which typically means that one of the IPs in the shared plan was blacklisted.
Since there are can be hundreds, sometimes thousands, of other senders using the same IP(s) in the shared IP pool, unfortunately, ignorant sending can affect the whole IP pool. In addition, we do have a Compliance team dedicated to keeping bad senders off of our platform, but it is inevitable that some will slip through the cracks, so these blacklistings can be intermittent.
Please know that SendGrid is unable to move accounts to different shared IP pools, but our systems will programmatically move accounts to different pools based on reputation and internal logic. SendGrid is unable to move IPs in and out of pools because it gives the impression of Snowshoe Spamming; A strategy where spam is propagated over several domains and IP addresses to weaken reputation metrics and avoid filters, which can make things worse. We do however proactively monitor our shared IP pools and attempt to mitigate all blacklisted IP’s as soon as possible. Despite this, sometimes just as quickly as we act to delist an IP it is relisted again. In addition, blacklisting services such as Spamcop do not allow manual delisting, and so we have to wait for an automatic 24-48 hour turnover to see if the IP has been mitigated.
We understand how frustrating mail deliverability issues can be and also the importance of email to your business. There are a few different options at this point:
- You could reach out to the network administrators for the domains blocking your mail to see if they are able to whitelist your sending domain (most often reached at [email protected]). This is known to be an effective mitigation strategy when dealing with rejections from smaller providers.
- Another option in this situation of course is to wait for the listing organization to delist the IP. Our compliance team monitors our shared pools and handles delisting mitigation and investigation into senders that cause listings. You should know that because the listing organization is in control of this system we’re unable to give an estimated time of resolution for this as the listing org may re-list at any time or prolong a listing due to subsequent complaints.
- The most decisive way to address this problem is to upgrade your subscription to Pro100k level, which uses a dedicated IP addresses to send mail. This would eliminate the possibility that other SendGrid users could negatively affect your sending IP’s reputation and thusly message deliverability. If you’re interested in going this route, please do let us know as we can offer a 25% discount for the first three months of your Pro subscription to ease the burden of switching to a more expensive plan.
All accounts that are on Pro and above packages utilize Dedicated IP addresses, and only accounts on Essentials and Free plans utilize Shared IP pools. Being grouped with others on a list of IPs can offer several benefits - it’s particularly affordable and the addresses are also kept warm by the volume of the shared users requesting mail through them. Unfortunately, unforeseen listings are a somewhat common issue when using an account utilizing shared IPs as your account is sharing IPs with many other SendGrid users. Regrettably, ignorant sending can affect the entire group’s deliverability. The benefit of a Dedicated IP includes the ability to control your own reputation, thereby avoiding blacklisting and deliverability issues.