Checking If GmailApp.sendEmail() Is Running - google-apps-script

Question

I'm trying to run a script to send automated emails to a list of people (I needed to edit out a bit of information).
function sendEmail(){
for (var key in emailBank){
var email = getEmail(key);
var bodyText = emailBank[key]['body'];
var commitmentType = emailBank[key]['type'];
GmailApp.sendEmail(key,"Subject Line", bodyText {htmlBody:bodyText});
}
}
I'm using an array (emailBank) to store information from a spreadsheet before sending it out. The function should loop through and send each person an email.
On occasion, I'm getting the following error: "We're sorry, a server error occurred. Please wait a bit and try again." for the line including GmailApp.
Can you think of any to verify if an email is sent or not? My concern is that half of the emails will be sent and half will not, so I wouldn't know who actually received the email and at which point the loop stopped.
Any ideas are appreciated here!

Answer 1

Ok, so I think I found a solution to this after trying out a few methods:
// Variables for error checking later
var emailRecipients = "";
var trueRecipients = "";
//The sendEmail function to send the email as expected
//It will also increment the emailRecipients variable
//only after the email has been sent
function sendEmail(){
for (var key in emailBank){
var email = getEmail(key);
var bodyText = emailBank[key]['body'];
var commitmentType = emailBank[key]['type'];
GmailApp.sendEmail(key,"Subject Line", bodyText {htmlBody:bodyText});
emailRecipients += key + "<br>";
}
}
//This function will only run if there was an error
//It will check increment all of the email addresses
//that should have been sent a message and then send me an
function errorEmail(){
for (var key in emailBank){
trueRecipients += key + "<br>";
}
var errorBodyText = "Emails sent to:<br><br>" + emailRecipients + "<br><br>Number of emails that should have sent:<br><br>" + trueRecipients;
GmailApp.sendEmail("example#gmail.com","Email Errors", errorBodyText,{htmlBody:errorBodyText});
}
function reminderEmail(){
try{
sendEmail();
}
catch(e){
errorEmail();
}
}

Answer 2

As a temporary solution, you could check the last sent email after calling sendEmail() method.
/* the search() method returns an array of GmailThread objects.
Pop() returns the GmailThread */
var threads = GmailApp.search("label: sent", 0, 1).pop(); // returns the most recent thread in 'Sent Mail'
var msg = threads.getMessages().pop(); //returns the most recent message
Logger.log(msg.getId()); //returns unique id for the message
Logger.log(msg.getTo()); //returns comma-separated list of recipients
One option would be to store the message id and check if it changes on each run of the loop. You may also directly compare email properties, e.g. the recipient's email, against the properties of the message you sent.