Apex Class Not Sending SingleEmailMessages [closed]

On production:

1. Check that the Process Builder is activated
2. Look through the debug logs to see if any governor limits are being exceeded

In the meantime, here's a bulkified version of the code (it doesn't address ensuring that you don't exceed per-transaction sendEmail call limits - for that you need some async processing):

public class CaseEmailFollowersNotify { @InvocableMethod(Label='Case Email to Followers Notify' Description='emails followers of new case email') public static void getCaseCommentIds(List<Id> emailIds) { // Get all the email messages using the given email IDs List<EmailMessage> emailMessages = [ SELECT Id, ParentId, FromAddress, TextBody FROM EmailMessage WHERE Id IN :emailIds ]; // Collect all the IDs for the cases associated with the email messages Set<Id> caseIds = new Set<Id>(); for (EmailMessage emailMessage : emailMessages) { caseIds.add(emailMessage.ParentId); } // Query all entity subscriptions for these cases List<EntitySubscription> entitySubscriptions = [ SELECT Id, ParentId, SubscriberId FROM EntitySubscription WHERE ParentId IN :caseIds ]; // Build up a structure holding entity subscriptions by Case ID whilst also collecting all // User IDs Map<Id, List<EntitySubscription>> entitySubscriptionsByCaseId = new Map<Id, List<EntitySubscription>>(); Set<Id> userIds = new Set<Id>(); for (EntitySubscription entitySubscription : entitySubscriptions) { List<EntitySubscription> entitySubscriptionsForCase = entitySubscriptionsByCaseId.get(entitySubscription.ParentId); if (entitySubscriptionsForCase != null) { entitySubscriptionsForCase.add(entitySubscription); } else { entitySubscriptionsByCaseId.put(entitySubscription.ParentId, new List<EntitySubscription> { entitySubscription }); } userIds.add(entitySubscription.SubscriberId); } // Neither of these are actually used here, but I have them to // demonstrate how you would actually manage this data in case // you actually need these objects in your full code Map<Id, Case> casesById = new Map<Id, Case>([SELECT Subject, CaseNumber FROM Case WHERE Id IN :caseIds]); Map<Id, User> usersById = new Map<Id, User>([SELECT Email, Id FROM User WHERE Id IN :userIds]); // Now process the messages for (EmailMessage emailMessage : emailMessages) { String tbody = emailMessage.TextBody.left(60); if (tbody.size() != emailMessage.TextBody.size()) { tbody += '...'; } // This code is likely to fail due to exceeding the maximum number of calls allowed to sendEmail // per transaction (see https://developer.salesforce.com/docs/atlas.en-us.salesforce_app_limits_cheatsheet.meta/salesforce_app_limits_cheatsheet/salesforce_app_limits_platform_apexgov.htm) // You likely need to handle this via async logic, breaking this down into smaller transactions for (EntitySubscription entitySubscription : entitySubscriptionsByCaseId.get(emailMessage.ParentId)) { // Neither of these variables are actually used, but are included to demonstrate how you would // deal with this data if you do need it in your complete code User user = usersById.get(entitySubscription.SubscriberId); Case case = casesById.get(emailMessage.ParentId); // Create and send the email Messaging.SingleEmailMessage mail = new Messaging.SingleEmailMessage(); mail.setHtmlBody('blahbalhblah'); mail.setTargetObjectId(entitySubscription.SubscriberId); mail.setWhatId(entitySubscription.ParentId); mail.setSubject('Case Following New Email'); mail.setSenderDisplayName('Case Following Update'); mail.saveAsActivity = false; Messaging.sendEmail(new Messaging.SingleEmailMessage[] { mail }); } } } } 

I've assumed you don't actually need to have global code since this invokable method isn't being exposed across a namespace boundary. I could be wrong in that assumption. However 99.999% of the time code posted in questions here doesn't need to be global.