Siemens S7 PLCs can send email notifications when something goes wrong in your process. If you’ve got an S7-1200 or S7-1500 it can fire off messages for motor faults, temperature excursions, I\/O failures, safety trips, or whatever else your alarm logic covers.<\/p>\n\n\n\n
The problem is that email notifications are easy to miss<\/strong>. They land in an inbox alongside everything else, and unless you’re actively watching for them, critical alerts get buried. A text message cuts through that.<\/p>\n\n\n\n Unfortunately, it’s usually much harder to get your Siemens S7 PLC to send text alerts rather than email ones.<\/p>\n\n\n\n Fortunately, we’ve got the quickest fix. <\/p>\n\n\n\n In this article, I’ll walk you through how to turn your Siemens S7’s email alerts into text messages<\/strong>. If you’ve already got email notifications working, you’re about a minute away from receiving texts instead. If you haven’t set up email yet, we’ll cover that too.<\/p>\n\n\n\n text.email<\/a> is an email-to-SMS<\/a> tool (and really, the only one you can use as an immediate drop-in solution). You send it an email, it shows up as a text on your phone.<\/p>\n\n\n\n Sign up, pick a private keyword for your account, and your delivery address becomes: Any email sent to that address arrives as a text. We’re going to put this address into your Siemens email notification configuration as the recipient.<\/p>\n\n\n\n If you already have email alerts working from your Siemens S7, skip to Step 3. If not… well, saddle up. They don’t make this part easy on you.<\/p>\n\n\n\n Siemens uses a function block called TMAIL_C<\/strong> to send email from the PLC. Their own documentation on it is thorough but dense. Here’s the condensed version.<\/p>\n\n\n\n This is the first gate.<\/strong> Your CPU needs to meet minimum firmware versions to send email natively over its built-in Ethernet port:<\/p>\n\n\n\n If your firmware is older than that, you’ll need to do either a firmware update, add a communications processor, or run a local SMTP relay on your network. Ideally, you can just do the firmware update because the other options are significantly more complicated.<\/p>\n\n\n\n Check your firmware version in TIA Portal under Online & Diagnostics \u2192 General \u2192 Firmware<\/strong>.<\/p>\n\n\n\n TIA Portal requires a project security administrator before you can import TLS certificates. If your project doesn’t already have one:<\/p>\n\n\n\n Keep these credentials safe; you’ll need them to open the project going forward.<\/p>\n\n\n\n Your PLC needs the root certificate of whatever SMTP server to which it’s talking. This is the step that trips up most people, and it’s the one Siemens forum threads are full of.<\/p>\n\n\n\n Important note about Gmail:<\/strong> As of the latest Siemens application documentation, Gmail\/Google Mail accounts are explicitly listed as not supported<\/strong>.<\/p>\n\n\n\n If you were planning to use Gmail as your SMTP relay, you’ll need a different provider. Microsoft 365, a facility mail server, or a transactional email service like Mailgun or Amazon SES on port 587 all work.<\/p>\n\n\n\n You can also use text.email’s relay<\/a> for a very quick solution.<\/p>\n\n\n\n Your PLC needs to resolve the SMTP server hostname. In the device configuration:<\/p>\n\n\n\n This one is easy to miss and will cause silent failures. TLS certificate validation requires the CPU’s internal clock to be within the certificate’s validity period.<\/p>\n\n\n\n A factory-fresh or recently reset CPU has its clock set to a default date that’s usually outside that window.<\/p>\n\n\n\n Sync the time via Online & Diagnostics \u2192 Functions \u2192 Set time<\/strong> (take from PG\/PC), or configure NTP synchronization under Properties \u2192 Time synchronization<\/strong>.<\/p>\n\n\n\n In the data block, fill in:<\/p>\n\n\n\n Connect the inputs:<\/p>\n\n\n\n On the output side, watch:<\/p>\n\n\n\n Common error codes: This is the simple part. In your TMAIL_C configuration, set the If you already had email working to a regular inbox, you’re just swapping the recipient string. The PLC sends an email, text.email turns it into an SMS<\/a>, and it arrives on your phone.<\/p>\n\n\n\n Force the trigger condition in your program (or use a manual trigger tag) to fire the TMAIL_C block. You should receive a text within seconds.<\/p>\n\n\n\n If it doesn’t arrive:<\/p>\n\n\n\n You already know why you want texts instead of email \u2014 that’s why you’re here. But it’s worth covering the landscape briefly, especially if you’ve tried other approaches.<\/p>\n\n\n\n Some automation engineers used to put carrier email-to-SMS gateway addresses directly into their TMAIL_C recipients. Addresses like Sadly, those gateways have been shut down. Verizon killed vtext.com. AT&T killed txt.att.net. T-Mobile killed tmomail.net<\/a>. If an LLM or a legacy forum post recommends using carrier gateway addresses, it’s working off old information.<\/p>\n\n\n\n The obvious next thought: use Twilio or another SMS API<\/a> to build your own pipeline. But sending application-to-person SMS in the US now requires A2P 10DLC registration<\/a> \u2014 including registering your business, your message purpose, and waiting for carrier approval. It’s the same registration process whether you’re sending 5 alerts a month or 50,000 marketing messages.<\/p>\n\n\n\n That’s a lot of overhead for “my drive faulted, tell me about it.”<\/p>\n\n\n\n PagerDuty<\/a>, Opsgenie, and similar incident management platforms can do SMS alerting. But they’re designed for software teams running distributed systems, not for a plant floor with a handful of Siemens PLCs that need to page someone when a VFD trips. The complexity and cost don’t match the use case.<\/p>\n\n\n\n text.email<\/a> exists because the carrier gateways died and there was no simple replacement. It’s not for marketing or mass messaging. It’s for exactly this kind of thing: a system that already knows how to email now sending SMS<\/strong>.<\/p>\n\n\n\n text.email plans include 200 SMS messages per month. For a PLC sending alarm notifications, you’ll be well under that cap most months. (And if your S7 is burning through 200+ alarm texts a month, the alerts aren’t the problem that needs attention.)<\/p>\n\n\n\n You can test it right now without signing up: send an email to<\/strong> Not every alarm your S7 generates needs to buzz someone’s phone. The goal is to keep texts reserved for the things where response time changes the outcome, and leave the rest on email or HMI logging.<\/p>\n\n\n\n The way you structure this in your TMAIL_C logic is up to you. Some people write separate TMAIL_C calls for critical vs. advisory, with different trigger conditions. Others use a single block with conditional recipient routing. Either way, the filtering happens in your PLC program, not in text.email<\/strong> \u2014 it delivers whatever email it receives.<\/p>\n\n\n\nSiemens S7 PLC Text Alerts: Table of Contents<\/h2>\n\n\n\n
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Setting Up Text Alerts on Your S7-1200 or S7-1500<\/h2>\n\n\n\n
Step 1: Sign up with text.email<\/h3>\n\n\n\n
yournumber@yourkeyword.text.email<\/code>.<\/p>\n\n\n\nStep 2: Configure TMAIL_C in TIA Portal<\/h3>\n\n\n\n
Firmware requirements<\/h4>\n\n\n\n
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Set up a security administrator<\/h4>\n\n\n\n
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Import the email provider’s TLS certificate<\/h4>\n\n\n\n
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Configure DNS<\/h4>\n\n\n\n
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Set the CPU clock<\/h4>\n\n\n\n
Add the TMAIL_C function block<\/h4>\n\n\n\n
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TMail_V4_SEC<\/code> (for IP address) or TMail_QDN_SEC<\/code> (for domain name) <\/li>TMail_QDN_SEC<\/code><\/li> <\/ul><\/li>\n<\/ol>\n\n\n\nConfigure the address parameters<\/h4>\n\n\n\n
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Wire up the TMAIL_C block<\/h4>\n\n\n\n
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yournumber@yourkeyword.text.email<\/code><\/li>\n\n\n\n'S7 ALARM: Motor Fault Line 3'<\/code>)<\/li>\n\n\n\n\n
#8420<\/code> is a connection timeout (firewall, network, or clock issue). #8530<\/code> is an authentication failure (wrong credentials or certificate mismatch).<\/p>\n\n\n\nStep 3: Set the recipient to your text.email address<\/h3>\n\n\n\n
TO_S<\/code> input to your text.email address: yournumber@yourkeyword.text.email<\/code>.<\/p>\n\n\n\nStep 4: Test it<\/h3>\n\n\n\n
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#8530<\/code> errors and you’re sure the credentials are right, the imported certificate may not be the correct root CA for your SMTP server. Some providers have changed their certificate chains recently.<\/li>\n<\/ul>\n\n\n\nWhy SMS Beats Every Other Notification Method for PLC Alarms<\/h2>\n\n\n\n
The old carrier gateway trick is dead<\/h3>\n\n\n\n
5551234567@vtext.com<\/code> for Verizon<\/a> or 5551234567@txt.att.net<\/code> for AT&T<\/a>.<\/p>\n\n\n\nDIY SMS pipelines aren’t worth it for alerts<\/h3>\n\n\n\n
Enterprise platforms are overkill for most shops<\/h3>\n\n\n\n
Get Your S7 Sending Text Alerts Today<\/h2>\n\n\n\n
yournumber@text.email<\/code> and you’ll receive the text in seconds.<\/p>\n\n\n\nWhich PLC Alarms Deserve a Text Message?<\/h2>\n\n\n\n
Always text<\/h3>\n\n\n\n
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Consider texting<\/h3>\n\n\n\n
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Leave on email or HMI<\/h3>\n\n\n\n
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Siemens S7 PLC Text Alerts: Next Steps<\/h2>\n\n\n\n