Swiftmailer rejecting valid email addresses if and only if submitted in array - php

Question

I'm pulling users' phone numbers from an s2member database and appending the wireless carrier domain name required to send SMS texts via email (Swift Mailer). So to create the array of email addresses I use the following (the function cellmap below just replaces the users' wireless carrier with the correct domain to append):
$matches = array();
if (is_array ($users) && count ($users) > 0) {
foreach ($users as $user) {
$user = new WP_User ($user->ID);
$matches[] = "'" . get_user_field("cell_no", $user->ID) . cellmap(get_user_field("cell_carrier",$user->ID)) . "'";
}
}
The resulting array looks like this, for an example of 4 matched users:
Array
(
[0] => '1234567891#vtext.com'
[1] => '3216549871#vtext.com'
[2] => '9876543211#vtext.com'
[3] => '6543219877#vtext.com'
)
Then I implode to create a string to use as the "To" field for Swift Mailer:
$cell_list = implode(", ", $matches);
which results in this (numbers are made up):
'1234567891#vtext.com', '3216549871#vtext.com', '9876543211#vtext.com', '6543219877#vtext.com'
Now I pass that to Swift Mailer like so:
$outgoing_message = Swift_Message::newInstance('')
->setFrom(array('no-reply#mydomain.com' => 'Mydomain'))
->setTo($cell_list)
->setBody($message);
// Send the message
$result = $mailer->send($outgoing_message);
And I get this error (ignore the phone numbers: they're made up, but correspond to the right ones in practice):
PHP Fatal error: Uncaught exception 'Swift_RfcComplianceException' with message 'Address in mailbox given ['123456789#vtext.com', '987654321#vtext.com', '5555551212#vtext.com', '321654987#vtext.com'] does not comply with RFC 2822, 3.6.2.'
I can successfully send any one of these emails individually via Swift Mailer, but when they appear as an array I always get the above error. I have tried applying trim to the individual addresses and the entire resulting string. A print_r of the array does not show any non-printable characters. I have tried various combinations of ->setTo($cell_list), ->setTo(array('$cell_list')) and anything else that might work, to no avail. I have tried replacing comma with semicolon in the list, and removing the single quotes around each address. As far as I can tell, the string of email addresses is in the exact format as shown in the Swift Mailer documentation. For the life of me I can't figure this out.

Answer 1

According to Swiftmailer documentation, setTo takes either a single email address or an array of email addresses as parameter.
Your code:
$cell_list = implode(", ", $matches);
$outgoing_message = Swift_Message::newInstance('')
->setFrom(array('no-reply#mydomain.com' => 'Mydomain'))
->setTo($cell_list)
->setBody($message);
Using implode() puts all the email addresses in a single string of text.
I suggest not imploding $matches:
$outgoing_message = Swift_Message::newInstance('')
->setFrom(array('no-reply#mydomain.com' => 'Mydomain'))
->setTo($matches)
->setBody($message);